Getting user input into ICU date offset macro

I am trying to write a macro that gets user input for use in creating an ICU date-formatted offset. For example, if the user inputs "10" on August 16, the macro will return August 6, formatted as 2014-08-06 for my purposes. The attached screenshot shows two things actually. The last action is a stand-alone, included so I just need one screenshot: it is an AppleScript that does exactly what I want, but it is hard-coded to use "10". I can't figure out how to get user input and use that input instead of the 10.
The other actions in the macro all build a text file that contains a user-inputed ICU date token as a line in a file, but I am not sure how to then process that as a token. I tried using a clipboard token inside the KBM ICU date minus token, but that doesn't seem to work (no recursive token processing perhaps?).
There is probably a very elegant way to do what I want but I just not techy enough to figure it out. I am basically trying to replicate a Text Expander script snippet that does exactly what I want, but doesn't seem to work in some File Save dialogs.
Thanks.

The ICUDateTimeMinus token is of the format:

%ICUDateTimeMinus%CALCULATION%UNITS%FORMAT%

Where calculation is any Keyboard Maestro expression (same as any numeric field), thus it can include variables unadorned.

The UNITS is Seconds, Minutes, Hours, Days, Weeks, Months, Years.

The FORMAT is the normal ICU format.

So:

ahh, it was the “unadorned” part that I was getting wrong - I was trying "%Variable%Offset%"
Thanks very much