Adding Sum Formula Using Cells Containing Alpha and Numeric

I've got a Column that has:

PP Ending 1-5
PP Ending 1-12
PP Ending 1-19
PP Ending 1-26
PP Ending 2-2

Etc... the column has 53 total entries... one for each week.

My issue is I have to manually type all 53 entries.

Is there a way to make a formula add these for me if I input the first one? I can't use a normal date format "mm/did/yyyy" because I have a macro that pulls the info out of these cells to name tabs and tab names can't have / in them. I even tried doing a customer format with - in it (mm-did-yyyy) but I still couldn't get it to work.

So... I used the aforementioned formatting instead... PP Ending, etc, etc.

With that being said... I am ok with changing the format to something different so long as the tabs can use the same name.

Hope that makes sense...

Thanks!

Holy cow, you're smart... fantastic! Thank you so much!