3 columns
1 row:
$X1
$Y1
$Z1
If there's a number in any of these, l want to trigger a concatenation involving the data in that specific cell.
The row will be filled in left to right. So, if X1 is empty, then Y1 and Z1 will be too.
If Y1 is empty, then Z1 will be empty too, but X1 may have...