Library proxy with intelisense

Question

I have quite odd scenario. I have external library like one below:

Now I need to use it in other solution but in quite unnatural way (but it needs to be like that :/). So it is included in such fashion:

As you noticed we have here new project named ExternalLib (just like the one we've created before in different solution). It contains only .dll of that library and we reference this project in Consumer (Add reference -> Project -> ExternalLib). Also I had to add one postbuild action for this 'proxy' ExternalLib copy /Y "$(ProjectDir)/ExternalLib.dll" "$(TargetDir)". It builds without errors. Only errors are displayed by Visual Studio text editor (as it is visible on screenshot above).

My question: is there any way to make visual know about that 'real' contents of that library? (I also do not own .pdb files) I know it is really odd way including external library but it is some constraint I can't avoid :/