Well not trying to sound like a jerk or only supporting Ubbthreads.
I have looked at other software myself.
Why would you think that someone here would write a export utility to import to another vendor.
For example would VB write a export utility to allow you to import to ubbthreads. I don't think so.
It would be the other way around.
Maybe you should be asking this question at the sites you are contemplating to migrate to.