I'm trying to copy and paste contents of a cell to another cell in order to
complete an entire column (about 300 rows).

The contents of the cell is a function which acts on data on two separate
worksheets.

I want the copy/paste to update some of the arguments of the function
(arguments that change with each row) but not other parts (arguments from the
second worksheet that don't change)

The problem is that everytime I paste the function, it wants to
automatically update ALL the arguments of the function.

What I'm trying to copy/paste:

=SUM(PRODUCT(E1,AH!B2),PRODUCT(F1,AH!B3),PRODUCT(G1,AH!B4),PRODUCT(H1,AH!B5))

to then make rows like this:

=SUM(PRODUCT(E1,AH!B2),PRODUCT(F1,AH!B3),PRODUCT(G1,AH!B4),PRODUCT(H1,AH!B5))
=SUM(PRODUCT(E2,AH!B2),PRODUCT(F2,AH!B3),PRODUCT(G2,AH!B4),PRODUCT(H2,AH!B5))
=SUM(PRODUCT(E3,AH!B2),PRODUCT(F3,AH!B3),PRODUCT(G3,AH!B4),PRODUCT(H3,AH!B5))
=SUM(PRODUCT(E4,AH!B2),PRODUCT(F4,AH!B3),PRODUCT(G4,AH!B4),PRODUCT(H4,AH!B5))
=SUM(PRODUCT(E5,AH!B2),PRODUCT(F5,AH!B3),PRODUCT(G5,AH!B4),PRODUCT(H5,AH!B5))
.... etc ...

What I'm getting is:

=SUM(PRODUCT(E1,AH!B2),PRODUCT(F1,AH!B3),PRODUCT(G1,AH!B4),PRODUCT(H1,AH!B5))
=SUM(PRODUCT(E2,AH!B2),PRODUCT(F2,AH!B3),PRODUCT(G2,AH!B4),PRODUCT(H2,AH!B5))
=SUM(PRODUCT(E3,AH!B3),PRODUCT(F3,AH!B4),PRODUCT(G3,AH!B5),PRODUCT(H3,AH!B6))
=SUM(PRODUCT(E4,AH!B4),PRODUCT(F4,AH!B5),PRODUCT(G4,AH!B6),PRODUCT(H4,AH!B7))
=SUM(PRODUCT(E5,AH!B5),PRODUCT(F5,AH!B6),PRODUCT(G5,AH!B7),PRODUCT(H5,AH!B8))
.... etc ...

As you can see in the first example; I only want to update the first
argument in each PRODUCT(X,Y)... but what I'm getting is both being updated
which doesn't work for what I'm doing.

I've tried copying and pasting cell by cell, copying and pasting multiple
sells, using Edit->Fill ..., and Paste Special - and I can't seem to figure
this out other than to manually enter this for every single cell (which is
prohibitively too labour intensive because what I'm actually trying to do is
much more complicated than this example)

If this makes any sense, I'd appreciate your help

- Thanks! Kevin