Adding "individual" numbers in Excel

Does anyone know of any function within Excel that can add each individual digit of a long number together to produce an added up version in the next column?

For instance, 7371 (seven thousand three hundred and seventy one) would be 7+3+7+1 = 18

I presume Microsoft haven't added any numerology functions, but it's worth a try.

its not a function, but Microsoft figured it out for you
put your 7371 in cell A1
then copy&paste this in B1

=SUMPRODUCT( (VALUE(MID(A1, ROW(A1:OFFSET(A1, LEN(A1)-1,0)),1))))

then change the number in A1
enjoy

heres the MS Support website that explains this nightmare

http://support.microsoft.com/kb/214053

I don't, but I've done a lot of that with various numbers. I started in the year 1999 with the number 666.
First I multiplied 666 by 1 to 50, added the digits of the products and graphed it - then 1 to 100 . . . I ended up going all the way to 3000. 13 was one of my favourites - I painted the graph on the door of my pu canopy.

At the time I didn't have a computer, and after all that work I found I could use Excel to make the graphs.