Make TS report success even though its task returns non-zero

Is there a way I can make a task sequence end reporting success even though the last task it ran reported a non-zero exit code?

I was going to try setting the _SMSTSLastActionRetCode and/or _SMSTSLastActionSucceeded variables to 0, but when I try to add either or those steps, I recevie a message stating "Please enter the valid task sequence variable".