Sorry for the link, I didn't knew about this forum policy. Anyway, thanks for the answer, it was the good one. I added the line to the batch file.

hi, it is my first post here. I've done some linux rpm packages containing an abandonware game and the good shortcut to launch it easily. All is working nicely except for some very old things that need to be slowed down. For those ones, I need a way to launch dosbox from the command line with 250 …