Pat GUI: How to do a message exchange session with an AREDN-connected WInlink gateway

I have the Winlink client software, Pat, installed on an Ubuntu system, connected only to our local AREDN mesh. We have the K7CPU-10 Winlink gateway connected to our AREDN mesh segment.  I can poll the gateway from the command line with "pat connect telnet k7cpu-rms-gateway.local.mesh", but I can't figure out how to configure the Pat GUI to do the same.  It seems to want to telnet the CMS only. 

Any suggestions on what the Pat GUI exchange settings should be?

Thank you, and 73s,
Collier
NM7B