Bitmap Permutations

[TK421]

How do you set bitmap permutations? I'm trying to replace gametype_options.bitmap in Guerilla, but every time I compile the bitmaps, I get gametype_options 1.bitmap, gametype_options 2.bitmap, etc.

[Ifafudafi]

Place all the images in the same file, but have each of them bordered by solid blue (r0g0b255) in a vertical line.