You won't see 1920x1200 in the game ... or game menu ... but the game should run at 1920x1200 if you do this ... from that thread I posted ...
Then once it is working try changing it to your desired res via the shortcut target ...
This ...
"C:Program FilesEA GAMESBattlefield 2BF2.exe"
becomes ...
"C:Program FilesEA GAMESBattlefield 2BF2.exe" +menu 1 +widescreen 1 +szx 1680 +szy 1050
or ...
"C:Program FilesEA GAMESBattlefield 2BF2.exe" +menu 1 +widescreen 1 +szx 1920 +szy 1200
... just change the res to your desire ... :D
you should be able to tell if it is at 1920x1200 ... if you can't then take a screenshot and see what size it is.
To add options to the target line of a shortcut ... in case you don't know how ... http://www.widescreengamingforum.com/node/8312
EDIT : You know editing your post after I post an answer is really annoying !