Hmm I use the Custom score. like, Every time a player kills 1 [men], it gives them one Custom point. Once they have 10 custom points it gives them a civ and sets the custom count to 0. as for every 100, could it be done with switches?

Uhm pls start another topic if you got a question... Its quite far away from what dragon asked. But anyways, heres the answer:

Again here's the answer death counters (DC).
Rename another unused unit (e.g. neutral - neutral - cave-in) to REWARD100.

Then always when the player gets a civ add an action to that trigger which adds 1 to REWARD100 for current player.
Another trigger checks if current player has suffered at least 10 REWARD100 and gives him the 100-kills-bonus and subtracts 10 of REWARD100 in the actions.