Topic: Images all in the same directory

I have a ton of images and thumbnails in many directories for many folder (thousands) and I am using simpleviewer pro and wish to customize it so that I can load a thumbnail by looking for the image name +"_sml" in that same folder

image1.jpg
image1_sml.jpg.

How do I do that? I can't find a concrete answer on the forums of what lines  I need to change.

Any help would be really great.

thanks
chris