Not really. You cannot trigger a macro based on entering or leaving a cell, and you cannot have a macro that is active only when you are in a certain cell.
You can have a macro that is triggered by whatever means (and active only in the specific application/window), and that macro could possibly determine what cell you are in by AppleScript, and if so then apply different behaviours depending on the cell. But it would require that there is some way to identify the cell by AppleScript, or perhaps by some other means. I don't know Excel, so I don't know what means might be possible.
Many things are possible with AppleScript, but you can't trigger a macro from an Excel worksheet.
Here's a trivial example:
tell application "Microsoft Excel"
tell active sheet
set theCell to a reference to cell "A1"
set cellValue to value of theCell as integer
set newValue to (cellValue * 10) as integer
set theCell's value to newValue
For help AppleScripting Excel please explore the following forums: