For the updated versions (gegenangriff, ausnahmezustand, AR 3.03 ) you have to use the newer conquer.eng from inside the EXPAND2.MIX, or if you don't have that, EXPAND.MIX.
For AR 3.03, you have to replace it back in EXPAND2.MIX because the game deletes the conquer.eng file in the RA directory.
If you just have normal AR, patch to 1.08 to get conquer.eng
ftp://ftp.westwood.com/pub/redalert/updates/RA108GP.EXE