How do you pass a value to a macro using vbscript?

[ambalboa]

I am trying to set a value for a macro using the Run Script action. I know how to pass a value from a macro to a variable, as in:

Set m = vbld_AllMacros()("VER_NUM") or

m = "%VER_NUM%

But now I want to do the opposite. I want (and I'm able) to get the version number of a file, but how do I pass that value to a macro? Let's assume the macro already exist. If the macro already has a version number stored in it, I would like to overwrite it. Does anyone know how to do this? Thanks in advance.