You could program this in blitz. Just use createImage to make an image big enough to hold all the images. Then load all the images and copy them to the new image shifting the X position for each image, and when done save the new image.
If you have 20 image that are 20x20 pixels, then create a 400x20 pixel image and copy each into x*20,0
Hope that made sense :-)
If you have 20 image that are 20x20 pixels, then create a 400x20 pixel image and copy each into x*20,0
Hope that made sense :-)