After the first concatenate i want to concatenate all the rows under th
checked boxes!

Be more specific

i have 20 cells in 800 rows

A B C D .... AA <-- columns
X X X ... <-- cells used as check box
Z Z Z ... Z <-- cells used as headers
1 3 4 5 ... N <-- cells with values

THIS =concatenate("A3";"B3";"D3") happens using the following cod
written by
Frank Kabel
------------------------------------

sub foo()
dim rng as range
dim cell as range
dim ret_str
set rng = range ("A3:AA3")
for each cell in rng
if cell.offset(-2,0).value = "X" then
ret_str = ret_str & cell.value
end if
next
range("A4").value = ret_str
end sub

----------------------------------------------------
Now , I want this to happen for all the next 800 rows

=concatenate("A4";"B4";"D4")
=concatenate("A5";"B5";"D5")
=concatenate("A6";"B5";"D6")