(not that easy ;-) ) (it may vary upon windows versions) (to my knowledge, this is not possible with the IR of hp49g+)
It's a bit like setting up a connection to Internet:
first copy mdmcbx.inf to c:\windows\inf (or something like that)
Go to control panel, then Modem, Add, Don't probe, select (on the left) VirginiaTech, and (on the right) Direct Connection, Next, choose the com port to which you'll plug your hp, Next, and Terminate.
We now have a fake modem, let's set up a fake internet connection:
Go to distant network access, Add, type whatever name you want, select the modem Direct Connection, and Configure
(that is the most important) within Configure, set the speed (9600), in connection, see in advanced to set Xon/Xoff, and do some logging. That should be ok.
Next, type any phone number,
right-click on that new connection, and select Properties:
See in 'type of server': uncheck:
click on TCP/IP parameters:
Type the following program on the hp:
\<< 13 CHR DUP 2 \->LIST CHAT PPPON \>>
(save it ;-) and launch it
then on win, launch the connection (type whatever login & password you want) and *pray*.
Well, ok, but I wonder what you will do with it: Zindoz doesn't have much things to bring to hp with regards to interneting ;-)
What you can do is to install Cygwin http://www.cygwin.com/ with its inetutils package, and then use inetd, just like in the Unix section above.
Argnn, I can't do much: both zindoz & usinagaz are bugged, and ppp debugging in that case is quite difficult without a dedicated machine in between (see http://youpibouh.thefreecat.org/download/analyse.tgz) Maybe merely retrying will work?