If you're using a MS PC then I think you have the following choice:
1. Setup the DSL IP as the default gateway as it requires it.
2. Configure manual static routes on your machine by:
- Opening up your DOS prompt and type
- route add mask
3. Test that the setup works. If works then you will need to go back to the DOS prompt, retype the command but this time add a -p (for permanent).
- route add -p .....