Problem solved...I modified the Outdial field of the mailbox to be Line instead of Pool, then specified a line in the middle of the PRI (they are a fractional, 13 channels, so I picked Line 00

. Had the mailbox user then setup RN to Pager with no '9' destination code ahead of the pager number (since it's directly on Line 00

and it worked fine!
So there is a glitch with RN on a MICS 5.0/NVM 4.0, but it CAN be overcome!