Is there a way to add text to a static text box using SetWindowText, or possibly another function, so that the previous text is not cleared?

how about using a function to add text to a box but using itself as an R value?

boxtext = boxtext + newboxtext

should give you the old text from the box with the new text.

As metamorphic said, you probably want to look at GetWindowText() and strcat() (or whatever you prefer for merging strings)...