How to use legacy COM component from metro application

Question

I find it difficult to use COM objects in a metro application. As indicated on MSDN, the following rules:

• Only free COM objects can be used.
• COM can only use APIs that are allowed for metro applications.

But my CoCreateInstanceFromApp always returns REGDB_E_CLASSNOTREG. In desktop applications, an error is logged in the event log that occurs when SideBySide is executed. But in the metro application, such an error is not written to the event log.

I can use the same COM object from a desktop application as a free registration on a similar manifest file.

Am I missing something? Can anyone help me out?

thanks