[fowlplay4]

If you're aiming for a bitmap text scheme you basically have to...

1. Convert the current character in text to a position on your image.
2. Draw the character using part of your image.
3. Move your drawing point next to the drawn letter.
4. Move on to the next character and repeat until text is completely drawn.

You could also do this using showimg, guishowimgctrls.

There's going to be a quite a bit of math involved though so good luck.