Thank you the support brother! I noticed that the encoding for the batch file in the code section was a little bit whacked, but the image in the spoiler tag shows how it supposed to look. Anyway the code is intact and I really love this system, and different emulators can use different flags and the example is using --libretro since I'm using RetroArch and a Libretro core. I spent way to much time on this over the years, probably more then I should have but all I have to do is to update the batch files once in a while.
you should learn vbscript and automate that. list roms and call retroarch/mednafen on them. use vbscript step by step by ed wilson. It's a great and simple language!