Close, but there is no "activate=(insert enemy name here)" command in FPSC X9. (Not even sure if it's in X10, but I can't say that for sure, since I don't have it! Lol)
You may want to take a look into the Tips and Tricks guide compiled by nickydude, and search for a script that opens a door when a few enemies are killed. I believe it's done using the "activateifused=X" command, and you can simply change the ifused property to the name of your last enemy.
The one and only,
~PlystirE~
Urlforce:
Dude, I'd rather be declared a dbpro noob than an fpsc legend any day!