You do not run functions (you run macros), you use functions to return a value to you. Once you have pasted (I'll assume my code because I'll be using my function's name below) into the module, go to any worksheet and put this in cell A1...

This is a test line with this (one.two@three.four.com) strange email address

Now, put this in cell A2 and I think all will become clear (well, I hope so because I am going to sleep now)...

=GetEmailAddress(A1)