I'm sure that ANYTHING is possible in OFP ! This game never ceases to amaze me and I've been playing it since 2001 !
I had a similar need in another mission I made. I wanted to make it seem as if the player had "9 lives" - every time he died I wanted to instantly respawn him and put up a message like "That was close" or whatever. Of course after 9 deaths the game was supposed to end, at that point something like "That one had your name on it !" was supposed to come up.
In your case I'm certain that it's doable with a combination of instant respawn, a vehicleDelete and an addaction. Try this (no guarantee of success) -
Set respawn to Instant and respawndelay to (say) 20. Have the following script run on the player (via his Init field or whatever) -
#loop
revived = 0
@!alive player
_body = player
_bodyaddaction ["Revive", revivePlayer.sqs"]
~19
@alive player
deleteVehicle _body
if revived == 0 then hint "You didn't make it !", deleteVehicle player
hint "That was close, but you made it !"
goto "loop"
Make another script called "revivePlayer.sqs" as follows
if revivingPlayer == 1 then exit
revivingPlayer = 1
player playMove "CombatToPutDown"
if random 1 < 0.2 then revived = 1, publicVariable "revived"
~3
revivingPlayer == 0
What the first script SHOULD do is create an addaction on your corpse while you lay there, floating over it. If someone can get to your body and successfully activate the addaction script within 20 seconds then you will come back, otherwise you will be removed from the game. In either case your body will be removed at the same time.
The second script runs when another player or AI unit runs the addaction. It only has a 1 in 5 chance of success, but if it works then it sets the "revived" flag to 1 so that you don't get wiped from the game after the respawn period has lapsed.
Notice that the 1 in 5 chance of success with each attempt taking 3 seconds means that you SHOULD survive if your buds can get to you quickly. Note also this variable is not "public'ed" so multiple players can work on you at the same time.
The part I can't vouch for is the deleteVehicle player. I've never actually tried to delete a player in game so I don't know if it will work (it should, fingers crossed !). I DO know that you the player are the living unit or your corpse, right up until you respawn. After that, you become the new unit and your corpse becomes a different (non-player) unit.
Finally, please note that the above routines have no provision for restocking your new persona with the weapons from the old body. Check out that revive respawn script by VB and see if you can cut and paste the relevant bits.
Good luck with it !
Roni