Hallo Gerhard

For a non-macro solution try this array formula
entered in C1. Not a beauty, but it will do the job :-)

=MMULT(TRANSPOSE(OFFSET($B$1,,,MIN(ROW()-ROW($C$1))+1)),
MMULT(N((MIN(ROW(OFFSET($A$1,,,MIN(ROW()-ROW($C$1))+1)))+
MAX(ROW(OFFSET($A$1,,,MIN(ROW()-ROW($C$1))+1)))-
ROW(OFFSET($A$1,,,MIN(ROW()-ROW($C$1))+1)))=
TRANSPOSE(ROW(OFFSET($A$1,,,MIN(ROW()-ROW($C$1))+1)))),
OFFSET($A$1,,,MIN(ROW()-ROW($C$1))+1)))

The formula must be array-entered, i.e. with <Shift<Ctrl<Enter
instead of <Enter, also if edited later. If done properly, Excel will
display the formula in the formula bar enclosed in curly brackets { }
Don't enter these brackets yourself.
Copy C1 down with the fill handle (the little square in the lower right
corner of the cell)

--
Best Regards
Leo Heuser

Followup to newsgroup only please.

"Gerhard" skrev i en meddelelse
...
Hallo ladies and gentle men,

I have two columns, A and B. I want to have a third
column, C, by multiplying column A and B in an inverse
order. That is to mean C1=A1*B1, C2=A2*B1+A1*B2,
C3=A3*B1+A2*B2+A1*B3, C4=A4*B1+A3*B2+A2*B3+A1*B4, etc. One
friend in this forum provided me the following subroutine.
I just copied it, paste it in VBE of the sheet I am
working on, and saved the workbook. When I want to do the
calculation in C1 by pasting the "doit" formula given
below, what I get is an error (#Name). What is the
problem? Please see the subroutine and the formula and
help out. Is there a non-macro version of solving this
problem?

Thanks

The subroutine is
Function doit(N, rangeA As Range, rangeB As Range)
Dim tempA(10), tempB(10)
j = 1
For Each cell In rangeA
tempA(j) = cell
j = j + 1
Next
j = 1
For Each cell In rangeB
tempB(j) = cell
j = j + 1
Next
mysum = 0
For j = 1 To N
mysum = mysum + tempA(j) * tempB(N - j + 1)
Next
doit = mysum
End Function

and the formula is

=doit(ROW(),$A$1:INDIRECT("A"&ROW()),$B$1:INDIRECT ("B"&ROW
()))