you can rename _m thumbs to normal filenames (the same filenames as the original large files) and move then via FTP to directory files/100/ This of course presupposes you also upload the original images via FTP to files/
Do this only if you upgrade QC 2.x to 3.2, otherwise just set up your webshop as you normally would. _m could be "small" in Polish.
I see. What you are saying is that the _m code helps to distinguish plain pix with their thumbs, right? If the thumbs are in a specific directory, here 100/, there is no need to rename them, right?