Getting the missing Windows functions

[Matt]

I have noticed that a number of the current Windows C functions 
are not in core.sys.windows.windows.d

I tried adding them to the module (after setting up source 
control so I can roll back any errors I might make), and found 
that Optlink wasn't finding the functions to resolve the symbols 
to. How do I go about getting the libraries that have the missing 
functionality, and once I have it, is it simply a case of editing 
the above module to make them available?