Is it bad to have accented characters in c++ source code?

I want my program to be as portable as possible. I search a string for accented characters, e.g. è. Could this be a problem? Is there a C++ equivalent of HTML entities?

It would be used in a switch statement, for example:

switch(someChar) //someChar is of type char
{
   case 'é' :
        x = 1;
        break;
   case 'è' :
   ...
}