*Thread moved to correct section.
Talk through and explain to me how you have done it so far?
You should of made your mod folder called @MOD1 (like you said) in that folder you need to have
another folder called Addons then within that Addons folder you need to put your .Pbo files of
the mods you want to use. Now once you have done that you should add this to your game target line:
"C:\Program Files\Bohemia Interactive\ArmA 2\arma2.exe" -mod=@MOD1
"C:\Program Files (x86)\Bohemia Interactive\ArmA 2\arma2.exe" -mod=@MOD1
(the 2nd one is IF your using Windows 7 x86)
That should do it!