Thanks for the reply. Clearly I have little knowledge of scripting.. I have placed the killing spree script in playerKilled - but with no effect, or error in the log file so far.
( Dev mode = CoD2MP_s.exe +set thereisacow 1337 +set developer 1 +set logfile 1 +set g_log server_mp.log )
The modified dm.gsc is being executed instead of the stock version for sure. And as far as I can tell, the script doesn't need sound files.

In the mean time I found out that the killing spree script was part of the Merciless Mod 2, so I will have a look at that and try to figure out if I can get the killing spree bit to run in my personal mod.
If so, I'll post it in this thread.