I am setting up a balance sheet and I have data in columns "E" and "F" that
show income and outgoings then in column "G" I have a balance. To get this
balance I use the formula:

=SUM(G6+F7-E7) and then drag the fomula down column "G".

However this leaves the total for that entry in cell "G5" to copy down
column "G" as well.

I tried using this fomula:

=IF(OR((E7="0"),(F7="0")),"",E7-F7)

Which hides the cell data which is fine but i want to incorporate the
previous balance (in the cell above (E6)) when i do that in the formula below:

=IF(OR((E7="0"),(F7="0")),"",G6+E7-F7)

It Just displays the total down column "G" as before

Is there a way to stop this happening or a way to trick excel in to changing
the unwanted data to "0" so I can hide it?

I hope you understand this Question I am really confused (and so might you
be) any help at all is greatly appreciated.