If you're talking about replacing the HASP key with either FlexLM or Sentinel, no you can't do this. The CAESAR II software is looking for specific responses from the HASP key, as well as user details which we stored there.

If you're talking about using the HASP key and its associated drivers on a machine also running FlexLM and/or Sentinel, there should be no problem. Aladdin claims both their hardware and software are transparent to other licensing mechanisms.