If you are going to the trouble of migrating from 4.0.X, I'd go all the way to 5.2 and ditch VMS and Win2K if you can.
If you have to use the same machine, the upgrade process "will allow you
to import your V4.x configuration items into the newly installed V5.0 system. It
will also allow you to migrate V4.x hosts to V5.0." (taken from the install guide).
I believe the migration information is stored in the \Program Files\Ciscopx\csamc\migration\export folder.
Tom