Hi there,
If you have a specific number of radio buttons to count, then you can just verify each of them.
Within the calculate event of a numeric field, you can count how many C and NC you have by verifying them one by one.
Create a variable for C and a variable for NC and each time you have C value, just add 1 to the variable C and same for NC.
When all radio buttons have been verified, just set the numeric field's value to the variable that you have been incrementing the value for.
Hope this will lead you the right way.