Wow. Ok, something you don't want to do is have long file paths. It would be a good idea to move the "paintball2" folder to "C:\", so the target field would read:
C:\paintball2\paintball2.exe +set dedicated 1 +exec theconfig.cfg
Also,
do not put "+set public 1" in the target box.
Only have it in the config file.
Btw, if your file path has spaces ("C:\Program Files\...) you need to insert double quotes, but not around the switches (+set ...). If you move the folder you will not have to worry about this.