"C:\Program Files\Cognos\cer2\bin\trnsfrmr.exe" -n -s " \\Servername\directory\Powerplay\Models\YourModel.pyi"
I use a bat file - if you have multiple cubes, I list them in one bat file and then call it with another bat file.
Easy to use in Scheduler too.Using UNC's if possible means any machine can run the file,otherwise you can get tangled up with mapped drives.