String character looping X++

Sometimes you come across offbeat requirements. One such was to iterate over characters of string to perform a particular operation. I googled and came across many examples of C#, small journey began to use CLR types for this operation using System.String but again it didn't feel right.

Then there was much simpler thought, which uses a native x++ function called subStr() to return each character. 

for (int i = 1; i <= strLen(_numString); i++) 
{
  int number = str2int(subStr(_numString, i, 1));
}

You could even put it as a global function to return character array from native x++ string. If you have any better way do share.