Position Swap in PA52.5 - through PFI?

Anyone ever done a transaction to initiate a "Move From Level" type of PA52.5 transaction? I can't seem to get past the "Must execute the Move from Level special action" soft error no matter what values I use in XMIT-HREMP-BLOCK (as well as some of the other XMIT values.

I need to be able to automate the switch of the primary and an alternate position - but just can't get by this error.

Anyone done this?