See Attached --->Sum CharacterValue Mix.xlsx

Running into an issue where there are values combined with characters and I need to sum them up. The issue is that this is in a range, and that range could have different characters.

In the attached document you will find cells with values such as T5, O4. If the range has only T's then the formula for that would look like this...
=SUMPRODUCT((0&SUBSTITUTE(C$4:C$11,$B2,""))+0)
Where B2 = T
if it were O then B2 would = O

Now in the document I am showing the general setup that I need to workout.
Which requires the sum of both stacked on top of each other, so T Totals on row 2 and O totals on Row 3 so really the above code, when it is O it is B3 but you get the point.

So I am getting Value errors and have tried a few variations of the above code.
This seems to be the closest to what I need but am still running into #Value errors.

Let me know if you know a quick solution to this problem -

Thanks -