make a simple percusion or drum loop in redrum...
minimalise lenght of samples to a wanted level...
conect it to the scream distortion....
use next or similar setings for scream:
damage control : around 50
type: digital
P1 : around 1:8
P2 : 127
cut it by th wish and adjust body by the other sounds in song
tips: change damage during the song to add the dynamic feel to it
screw around and see what you get you can even duplicate redrum and make one clean and one distorted and use it for crosses and stuff