Charles MacDonald wrote a utility to convert HES files into PCE files -
here. Don't worry about the source files, just drag and drop the HES file onto HESFIX.exe. You'll have to rename the .hes file to .pce so it can show up on the flash software/loader.
Also, the tototek card I have does not like roms smaller than 2 megs so I have to pad them to 2 or 4 megs. If you need a utility to do this, I could write within a day or so.
Once you get the converted file loaded and running on the PCE/TG - use button I to cycle the next track. I wouldn't use any other buttons because it tends to crash (invalid track I think).
If you have any problems, just send a PM.
-Rich