Substitute and sum values from multiple cells

Hi there,

I have a row of cells some of which containing the letter 'H', and I want to be able to count the number of H's.

I believed I could do this with either the substitute or vlookup function such as:

sum(substitute($A1:$A5,'H','1'));

But these functions do not appear to work for a range of cells, can anyone advise me how to do this?

Thank you

James