Global Functions, Variables etc. Setup help in excel 2010

Hey guys,

I'm working on a macro that involves a bunch of the same kind of loop, just with one slight difference to each (the column, which is determined by input from a ComboBox). I'm using whatever version of VBA comes with Excel 2010.

First of all; where/how do I declare global variables? Also, can I go to the same place where I declare global variables (if there is one) and make a Global Subroutine or function or something, that I can then just make a call to in my code?
So like I write a loop, but where I need to specify the column I fill with something else, then in my "Private Sub" I can just make a call to said Global Subroutine, and from the Private Sub, specify which column I want it to start in?

I want to do this because I think it would save me from having to write out the same two loops over and over again!


Thanks!