I have resolved this issue with a simple validation check - though I cannot get it to work with a tolerance between $100 and -$100.
In OB28 I set as follows:
Prerequisite: BKPF-BLART = RE
Check: BSEG-SAKNR = 123456 (GL account we do NOT want posted to)
Message: Error - PPV posting to account 123456 is not allowed. Use account xxxxxx
This message appears in MIRO in the messages at the top. It also appears during simulate.
Regards,
Cheryl