I'm having bother with the IF function.

Cell A1 contains a figure derived from another worksheet.
Cell A2 contains 4895
Cell A3 is A1-A2
Cell A4 contains 2090
Cell A5 is A3-A4
Cell B3 is 10% but I'd prefer it to be referred to as B3 as this figure may
change

If A3 is less than 2090 (A4) I want C3 to be A3 x B3
If A3 is a minus figure I want C3 to be zero. If A3 is greater than 2090
(A4) then I want C3 to be A4 x B3

This is the simplified version of it. Any attempts at solving this on the
real worksheet result in circular references.

Any help would be appreciated as a big fat computer monitor is about to find
itself being thrown through the window of a first floor flat onto the street
below.