USB Pass Through / Com Port Via Named Pipes

I am currently in need of redirecting a Com Port to a Hyper-V Guest via named pipes from the Host Machine.

I cannot find any good documentation on the subject.

If Hyper-V supported USB Pass through like ESXi does i would just plug a USB Serial port and be done with it.

But alas Hyper-V seems not to support either.

How are people supporting older COM Port requirements on newer Virtual Machines?

And yes I have ESXi Servers, but in this particular implementation the Customer wants Windows 2008R2 Hyper-V.