How can I change a room mailbox's calendar display name?

I have a Room Mailbox Calendar, that  I can't get to display right.  I'm trying to change it's name and have not been able to figure how to change its "Display" from Meetroom 2 (West) Calendar to "Back Office"  

I've set it's -name, -displayname, and -simpledisplayname yet nothingseems to effect the "Display: " field and outlook still displays the old name even after a day.

Thank you!