Telstra wireless modem Maxon BP3-EXT

[Geoffrey Combes]

Having installed Ubuntu 9.04 I have connected with Canon printer and 
scanner without difficulty.
However I have been unable to recognise my Telstra wireless modem (Maxon 
BP3-EXT). Telstra state that they do not support  only certain versions 
of Windows and Mac. What they mean, I believe, is that the software 
provided is written for Windows and Mac; something I know already - 
that's what the software disk packet says.
Given the right driver and other files plus instructions on their 
installation I am sure that Ubuntu 9.04 can connect me to my Telstra 
Wireless Mobile ISP via the BP3-EXT modem. I have downloaded a Sierra 
driver and ppp file ostensibly for connecting Linux OSs to this Maxon 
modem, however I am not sure that this is the correct approach.
As I suspect that someone has done this already in Australia I request 
assistance from the Ubuntu-AU community.
Geoffrey Combes (new user).