InstallLib on Vista with standard user problem

I have COM library that is registered per user under HKCU. The installer is executed with "user" RequestExecutionLevel. The problem: in case library is locked (loaded by other program), register-on-reboot is not working, because InstallLib writes to HKLM to do it.
Starting installer as admin will not help as then library will be registered for the admin user.
Is there anything I can do?
Thanks!

There is no method I know to replace a file on reboot without administrator rights.

I understand, so it's kind of a loop.
The bottom line that on Vista, regsiter/copy-on-reboot will not work for per user registered libraries.