Ah, I had to do that for my OS menu. The way I ended up doing it was like this:
Code:
std::string foo; 

std::ostringstream oss;
oss << *integer/float/string/etc.*
foo = oss.str();
And then converting foo to a wstring and then wcstring whenever its needed.
Code:
std::wstring widestr(foo.begin(), foo.end());
wcstring bar = widestr.c_str();
Might not be the best way of doing it, but it works.