RSA certificates and Routers

I have a Netcomm NB5540 router which has the capability to act as a 
L2TP VPN endpoint.
I need to make a VPN connection to my ISP, and they have provided an 
RSA certificate for a PC (Windows XP/2000)

Is there any way I can use this certificate to make the connection with 
the router ?

I do not have, and do not want to have, a Windows box. I run Solaris 
and MacOS X at home and would like them both to connect to the ISP via 
the router.

The ISP does not have any experience with this sort of thing - it is a 
new setup, using a wireless link via a Proxim Tsunami modem to the POP, 
then creating the VPN link to access the internet. They have a 
preconfigured package with Windows certiticates and instructions and no 
idea how to do it with other clients.

I do not have a choice of ISP due to my locality - the only other 
option would be modem dialup!

If it is not possible to use the RSA certificate with the router, is it 
possible to use the certificate with either Solaris or MacOS X.
The Mac has a L2TP client but no easy way I have found to import or use 
certificates.
I have found some info about Apple using KAME, but no details on how to 
use this to import the certificate.

I found this list address via a link from the ISP - I am not subscribed 
to the mailing list so please reply direct to me.
How do I join the mailing list?

Any info gratefully received.

cheers
Frank

[email protected]
Sun Australia