Formula Problem: SUMPRODUCT (Count cells with text, excluding blanks and two names)

Dear Excel Forum Members,

I have a problem with the SUMPRODUCT. I have multiple kalender months excel fill with names in their that I need to count in order to het occupancy rate, but I need to exclude two names "David" and "Bryan" and blanks from the count. So far I have tried multiple formules Countif, Countifs and lastla Sumproduct. The last has been working but only for one name and for one collum. I want to select multiple column as my range, so I don't have to do it 1 by 1. One forumla has been working so far, but like I stated above just for one column.

Formula: =SUMPRODUCT((L4:L11>"")*(L4:L11<>"David"))

I have uploaded the file for one month.

I would really appreciate it, if you could help a fellow member out.

Thanks in advance!

With kind regards,

Danny

maybe like this?

=SUMPRODUCT(--(C4:AG12<>"David")*(C4:AG12<>"Bryan")*(C4:AG12<>""))