Sorry I should have read twice your question. I had the impression
that it was the browser that was blocking you from accessing the web
site. Are you trying to launch the remote desktop via the MS web
interface ??? If yes, I think that this is simply a web interface
that call the MS Terminal Server thru an activeX of an ASP program.
Why not call yourself directly "rdesktop" the linux terminal server
client ? Once you are connected to your company network via modem,
the internet or a vpn you can reach a terminal server with rdesktop.