The target line should look exactly like this (if you use the default install location)
Code:
"C:\Program Files\Star Wars Jedi Knight Jedi Academy\GameData\jasp.exe" +set fs_game dfmod
I'm not sure if you mean to have those quotes there or are just using to show what you're adding, but messing up the quotes in the target field can cause it to give the 'not valid location' error