I haven't actually tried this, but maybe something along these lines
will work...

1. In Declarations, dim a variable such as UserVAL as Public
2. Modify your macro  -- base it on UserVAL.
3. When your macro is launched (by command button, the change event of
the textbox, or whatever) set  the value of UserVAL to the contents of
the textbox.
4. Then run the macro.