Get the Dll Handle for multiple Addin

I wanted to know if it's possible to get the dll handle of another application from a toolkit application if both the applications are registered using registry file Prodev.dat.

Scenario: Suppose I am loading two add-in/plug-in DLLs at a time through prodev.dat file.
Internally, i want to get the handle of each DLL, to communicate internally.
Is there a way, i can get the DLL handle of each plug-in.

Steps tried: Suppose, I am loading A.dll and B.dll through prodev.dat.
When both gets loaded, I called toolkit API ProToolkitDllLoad() and passed B.dll path to get the B's handle.
But, the API fails.
If I try to call, ProToolkitDllHandleGet() , I don't have the first argument i.e. ProName application_id
Query from PTC team: Is there a way, i can get the Handle of B's DLL?