If there is only one unit type or one unit type at a specific time, then do:
Where <NUMBER> is the number found in
here for that specific unit.
| Trigger |
| Conditions: |
¤ Current player kill score is at least <NUMBER>
|
| ¤ Anything else if needed |
| Actions: |
¤ Subtract <NUMBER> kills *score*
|
¤ Add # custom points
|
| ¤ Preserve Trigger |
If there is multiple unit types (or your lazy

), then just do what vic said.
EDIT: Fixed.