Gurus: Powerbuilder 6.5 / .NET Server side communication?

Hi,

I need some help from all ye experts with the neat tricks up your
sleeve.

Scenario:  Legacy PB 6.5 Client/Server app needs breath of life.
.Net code can perform needed server side functionality.
Need PB code to call server.

Issues:    Wish to avoid ugly PB socket to communicate with web
service.
Server side call may take a few seconds to run.
Wish to avoid PB threading.

More:      So we begin a PB application function, select a few options
- at this point making an asynchronous server call would be great, I
need to finish the function and at the end find out the result of the
server call (and display).

Perhaps:   Anyway PB 6.5 can use a .NET DLL to perform a remoting
communication?