Try modifying this to what you want...
First, add reference to the namespace
Microsoft.VisualBasic
this, allows
Strings.Mid
to be available.
using Microsoft.VisualBasic;
string First = "Hello";
string Test = "Wello";
int unMatch = 0;
int Place = 1;
foreach (char current in First)
{
if (Place == Test.Length) break;
if (current.ToString() != Strings.Mid(Test, Place, 1))
{
unMatch++;
}
Place++;
}
MessageBox.Show(unMatch + " unmatched character(s) found.");
}