Can I make Excel assign a numerical value to a cell with text?

[noisy]

I know this question has been asked in slightly different formats. But I didn't find an answer to my particular situation. I'm using Excel as a reservation form for an RV Park. I enter the guests last names in the cells corresponding to the applicable day (columns) and space number (rows) they're in, per month (sheet). I'd like to be able to do a basic calculation of occupancy. Can I get Excel (2010 version) to assign a 1 to any cell with letters? I don't want it to assign a 1 to any cell with numbers already in it (date or space numbers). Then I could have it do an auto sum by row (space numbers) and have a total occupancy rate for each month? Ex: if there was a name in seven cells for the row for space #9, Excel would total 7 for that month, meaning space #9 was occupied 7 out of 30 days. Clear as mud?

[daffodil11]

=SUMPRODUCT(NOT(ISNUMBER(A1:AE50))*1) would count a 1 for every cell not containing numbers

Maybe even use

=SUMPRODUCT(NOT(ISNUMBER(A1:AE50))*(A1:AE50<>"")*1) to skip the blanks as well

[noisy]

Would it count blank cells in that row?

[daffodil11]

Good to see I was on the right track with that quick edit.

[noisy]

Thanks much!