I was trying to append a DWORD variable at the end of a LPCWSTR in order to pass it to a CreateProcess as the command line argument, but I haven’t found a way to do it.
My best guess is trying to concatenate it with a casting, like this:

wcsncat_s(string, (wchar_t *)id, 8);

8 is just to put something there, and id is the DWORD variable.
I appreciate any insight and will add any code you believe neccessary.