summing part of a string, excluding cells

[soph]

Hi!

I have a very similar question to that posted by Arturo. I have a column of
cells to sum where each cell has either a letter and 3 numbers or simply an
"X".
eg: a1 = C6.5
I can use the formula advised

[soph]

Please check my next post as I posted this before I had finished!

"soph" wrote:

> Hi!
>
> I have a very similar question to that posted by Arturo. I have a column of
> cells to sum where each cell has either a letter and 3 numbers or simply an
> "X".
> eg: a1 = C6.5
> I can use the formula advised