Workaround for nested RDP?
Solution 1:
Nested RDP (If you mean RDP in to a RDP) is annoying, but your best and quickest bet.
Other than that, have you tried different virtualisation software?
If you are talking about Microsoft Virtual PC and your new machine does not have the VT bit, you may want to take a look at Sun Virtual Box... It works fine and has lesser requirements than Virtual PC or VMware Workstation.
Solution 2:
You may be able to use something like netcat or fwop to proxy the TCP connection - though be aware most anti-virus will flag both of those executables and probably throw a fit.
Solution 3:
Not unless you set up some kind of RDP proxy on your laptop.
The latest SecuRemote/SecureClient should work on Windows 7, although is not mentioned as officially supported on Checkpoint's site. Checkpoint needs to get on the ball with this one....