What's the problem with DLLSurrogate? It's the reliable solution. If you want to use an external 64 bit application you just can create the object and pass the moniker (for example ObjRef moniker) to 32 bit application.

https://www.vbforums.com/showthread....=1#post5384139
https://www.vbforums.com/showthread....=1#post5572129