Hi Hakka,
You can export the old workspace data and import to a new workspace using stsadm
export/import.
But the both instances of old meeting workspace and new meeting workspace will display in the new workspace.
Just like that many meetings link to the one workspace, it will create many different Subjects (with different instance ID) with each meeting name in one workspace.
You can try with stsadm and check the effect.
Note: When you use the stsadm –o import command, you need to import the data to a workspace URL.
If not, it will fail because of the site template mismatch.
Thanks,
Daniel
Regards, Daniel