I got one of them as well a model 6365, and i never worked out a way to do it.
However assuming you also have a home/office/other pc, which can remain connected to the internet while your away.
I would suggest you use The PocketPC's Terminal Services Client to attach to your home pc, and do your mircing from there.
(in case your not familar with Terminal Services, it lets you logon and/or (or only in server os's) takeover the pc, it essentially emulates your other pc on the local one.)
* its great as you can leave mirc running, but not inccur the higher rates for celluar based internet (if you cant find a ir/bluetooth/wifi connection).