Yes you can, but it takes more than a script snippet. You need:
1) Two missions (obviously)
2) A description.ext file in each mission
3) A campaign folder with a third description.ext
If you want to fade a mission into another you need to make a campaign from them. Then you can configure your campaign so that mission1 is followed by mission 2 (without briefing/debriefing)
The description.ext in the campaign folder tells OFP what mission will follow when mission1 ends (in this case mission2). The description.ext in mission2 will contain information that tells ofp to start the mission without briefing.
I will not go into any more detail now. Have a look at the tutorials. I can help you with specific questions later.
There are easy to use campaign tutorials in the editor depot