Hi,
sure, there is:
1. add an additional VR(F) or use an existing one different from the one currently used for accounting
2. configure a radius accounting server in that VR(F) (if not already present)
3. configure "aaa accounting duplication <name of the VR(F) from steps 1./2.>"
Please let us know if this works.
Best Regards
Ulf
P.S. I made that sound very easy. The drawback is that the VR(F) needs to have connectivity to the additional radius-server, which is not easy to achieve in all environments.