It's possible, but I'm not clear on what you are trying to do.
How will you use this method to avoid having 26 buttons? Normally, you'd still have 26 buttons but each would pass a different parameter to the same script--resulting in 26 buttons, but only one script.
If that's what you want to do, it's as simple as opening button setup... for the button, clicking specify and typing the appropriate letter into the optional script parameter box.
I have it working with individual letters, But I am trying to do it with only 12 buttons and assign more than one letter of the alphabet to that button, is this possible?
How do you expect to get 12 buttons to take the place of 26?
I'm trying to picture how you expect that to work for you. What does the script do that is performed by these buttons?
Do you want one button, for example, to perform a find for all buttons starting with a or b?