I really doubt it is possible. Virtual appliance (vApp) is a lock-down OS, therefore it does not provide a way to move the 'backup file' off of the vApp, unlike Windows/Linux/Virtual Machine. Usually, if you are running UM on Windows/Linux/Virtual Machine, then it is possible to 'backup' and restore the 'database' to another UM of same type. With vApps, VM/datastore level snapshots are used for backup and restore purpose.
My suggestion would be to: 1) Get the vApp up and running and it will start gathering newer stats. 2) Power-off the Windows-UM, after a month or so, so that you have month-old data collected on the vApp. In case you want to go back to old historical data, you can always power-on and get the old stats, usually a month old data is good enough for analysis and troubleshooting.
Interesting if you look at the documentation for AIUM, there is a provision to - Migrate vApp UM to Linux system. Perhaps, b'cos they both speak linux.
NetApp TS should be able to get into the appliance as "root". I haven't run the appliance since version 6.0, but back then they possessed the secret decoder ring and were able to get in. They should be able to assist you I getting a copy of your backup file from your Wintel host to the appliance, and kicking off a restore. Of course, all of this hinges on the appliance being able to restore from a Wintel-hosted backup. Again, NetApp TS should know. All of this is exactly why we went from the appliance )(the only choice back then) to a RHEL-hosted installation the second it became available - it all came down to control. We've never looked back since, and we've never been sorry we switched from the appliance to the hosted solution.
Good luck, and I hope that this works out for you!