Is it possible to use a macro to change another macro.

I have two Module level constant that i use

Const numCol As Integer = 19
Const numWS As Integer = 3

Ideally, these number can change automatically. It won't work if i delcare a
const with something such as Const numWS As Integer =
Application.WorksheetFunction.CountA(Worksheets("S heet1").Range("G:G"))

How can I make this work? I am thinking that maybe calling a macro in
another module can change this.

Steven