Güten abends.

I could use some help on how to define a value for a ListBox choice. I've started making a little program called Message Maker, where I construct Windows dialouges.
some example code:

MsgBox txtMessage, ,txtTitle

As you can see I got the values I need for the Title and the message, but I still need to know how too get a value out of a listbox and putting it in there between the commas.
For example I have a value in a listbox called "OK", I want that value type in vbOkOnly between the commas.
Does anybody know how to? BTW, is there any good beginners forums around?