Hi, can anyone help with this? I need formulae which demonstrate a flow in
one direction. I'll put it a simply as I can.

I want to be able to add manually, a value to cell 'A'

When I manually subtract value from cell 'A' a formula adds that value to
cell 'B'

That much I could do but it is conditional upon the following.

For this to work I then need to be able to manually subtract from values in
cell 'B' without the formula in the first stage returning that value to cell
'A'. It has gone elsewhere, not back to where it came from.

Can Excel do this?

Help much appreciated.