That's simple enough, considering that's a C API, and not an genuine Nim's library. C doesn't have Nim strings, so you copyMem your string to its char-array; not such a problem. You can find all constants needed in `MinGW/include`, just make a text-search over the folder (matter of seconds); they are taken initially from there to `windows` module, and you can of coarse update it.
Explanations of API functions and constants are in WinAPI Help, you probably have that with your programming tools; the docs are surprisingly good and easy-explorable, mostly you won't even need to search the web (though that is there too). I have it in hlp-format, there you enter in **index** `CreatePopupMenu`, and get the spec for the function you need, links to related functions (`InsertMenuItem`, ...) and **overview** button for the general information; a search and hierarchial contents are also there; that's really well-organized, not some mess of texts. But certainly that won't be a single line to write, so was the advise to search first in existing Nim libraries.
