Script that edits the text printed on the button that runs the script

I need to add a line to a script that changes the text on the button that runs the script, but I really don't want to use selections of any sort if possible. I ran a macro and the macro, of course, used:

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but .Characters.Text doesn't work directly with ActiveSheet.Shapes. Is there something else I can use, or am I stuck selecting the button?

Thanks!