...Yes.
How to make it a sqs:
Open up your script in any Word Proccessing Program, Click on File/SaveAs/. Then, when the Window pops up, right below the part where you can name your script, there is a format selector. Select "All Files", then Move up to the part where you need to name is, type "yourscriptname.sqs" (with out Quotes) and then where ever you saved that file to, it should say your script name and the format. (sqs)
Script Activation:
Just like Black_Feather said, you need to put your script in your C:\Program Files\Codemasters\OperationFlashpoint\Users\Yourname\Missions\yourmission (default) Then, When you have that script placed in your OFP Root Directory, create a Trigger, then on activation type "" exec yourscript.sqs (including the Quotes). When you create the Trigger, be sure that you Set "Activated By" on Anybody. (It can be East, West, Gamelogic, Resistance, Civilian, Anybody, or Any of the Radio Channels. Doesn't matter) Then this should open your Script in-game!
If you have any more questions, Send me a Private Message through through the forums, or write me an E-Mail. (Swatdog6488@hotmail.com)
Good Luck,
Swatdog