Chain summing in Excel

I have this table:

   Sendedr Reciever Price  SumAllParice 
   Dan      Moshe    A
   Kate     Sara     G
   Beth     Kith     U
   Moshe    Kate     X

(actually, it's much more bigger, it's just an example). I what to sum all the prices like this: "dan" is se开发者_如何学Cnding "moshe" A, and the (according the table) "moshe" sending "kate" X, and then "kate" will send to sara G so in the "sumAllPrices" in the first row will be A+G+X. in the second row will be G (because after kate sending sara, sara dosn,t send anyone else), in the third row will be U, and in the fourth row will be X+G (because after moshe sending kate, kate will send to sara. How can i do this in Excel?

I found the answer. it's a little bit limited' but it works!

• I entered an image because it all meesed up when i copied it from the excel...

Explentaion: The 1rst iteration is to sum the first row with the second (e.g if Tin sending Dan, and Dan sending moshe, so it will be R+A). The second iteration act the same, but it sums the sum column with the first iteration by those rules, and so on, untill the answer is the sum of the sum column with the third iteration column.