Yes, it really is as simple as that! Before reading @Frankb's reply, I made two test macros to work it out for myself, and they look the same, and they work.
So, @Donald, you might want to make two macros, one with the action to set the global variable (as shown in the first image), and one with the action to read the variable (as shown in the second). Then you can assign a different trigger to each macro.
It would be possible to combine them into one macro but that would add unnecessary complexity, I think.
Yes, fair comment if step 2 is needed. Your interpretation of @Donald's aims is different from how I read it. I took the pointer question to be the full extent of the task but indeed he may well have a greater ambition for his macro than the second paragraph encouraged me to believe.
Thank you all so very much for everyone's prompt reply. I really appreciate that.
I was able to get the actions to work, but the variable %CurrentMouse% didn't work for me, even though it seems like it should. Possibly it didn't work because I set the mouse a different position within the macro and the variable mouse_position was updated automatically to the new mouse position.
To keep that from happening I'd probably have to add an action something like mouse_original=mouse_position and then at the end of the macro use mouse_original to set the mouse position back to the original position. Because I don't know the syntax for basic math in this program, I changed %CurrentMouse% to %Calculate%MOUSEX()%, %Calculate%MOUSEY()% and then the macro worked for me.
Frankb, there is no other way to change an exact zoom level in Lightroom that I know of, other than pointing and clicking (but I am no expert). I like the idea of a macro because I tire of the eye-hand exercise that Lightroom forces me to do so much. I am going to try these macros on a stream-deck or a tour box.
tiffle, I didn't expect the restore mouse position would work, but it did! Wow. What a cool thing to learn. Thank you!
To zoom in quickly and easily, you can use this handy keyboard shortcut: CMD and + key . To zoom out, use the CMD and the - keys. If your first zoom doesn't get you to the magnification you desire, do it again; it will zoom in closer each time.
Ah, but it probably doesn't give you the exact zoom level you want.
Probably because these questions often involve multiple "move and click"s -- while you can do each of those as a "move, click, restore" you get annoying extra pointer movements.
It doesn't work like that. Your mouse_position variable is set to the evaluation of the %CurrentMouse% token at the moment the action is executed -- since there's no "auto-update" and you don't set mouse_position to another value during your macro it should work...
But it looks like you've extra text in the field, after %CurrentMouse% -- see how the action's name has ... after the %, indicating that there's more to show than there's room for? So mouse_position is an invalid value for coordinate-setting when you come to use it in the last action. Make sure you've no rogue spaces or linefeeds in there and that should solve your problem.
As a wise person never actually said: "Give a man a 'Save current mouse position' action and he'll be able to save his mouse position. Teach him how to roll his own using KM fundamentals and he'll be able to automate anything ".
But the most important fundamentals of all are:
Work out what you want to do
Break that down to the simplest steps you can
Try and work out how to do each step using KM's Actions, Tokens, etc
If stuck for more than 5 minutes, don't beat yourself up -- we've all been there. Post your problem here, following these guidelines and ideally uploading a sample macro, and help will soon be at hand.
Welcome to KM, and welcome to the Forum!
 Some hyperbole may have been employed in the making of this statement. The value of your macro can go down as well as up, etc, etc...
Frankb, I was surprised that the actions you mentioned aren't a part of KM. Probably too basic for experienced programmers, but us beginners would appreciate them.
The last time I tried to program a computer was about 45 years ago, on an Apple ][ computer in basic. I never took a class, but I could do For Next Loops and print "Hello World" on the screen. Applesoft Basic made my head spin, but I did learn some of the logic of programming. I knew I could never be a programmer.
If the developer of KM could make it easier for non-programmers to create simple macros by providing some simple pre-made actions (even knowing that experienced programmers don't need them), I think the appeal for KM would grow, as not everybody is a programmer. Many people have some simple programming skills and they might be excited to try KM if it was a little easier to get started.
I have found your help and those of others really terrific, and I will plod along knowing there are helpful people here willing to lend a hand. Hopefully KM can be made a little more user friendly for beginners in the future