What is the best method for manipulating an x64 COM API from VBA or VB6. I need to make calls against the API and return values. I expect to need to make some sort of .Net Wrapper because you cannot load the x64 dlls into a 32bit runtime, I am looking for design recommendations on the communication between the processes. I would prefer a good MSDN reference, because I need to prove definitively a best practice. I have already tried searching MSDN to no avail, so I am turning to the experts.