Format Cell Font (Type & Colour) depending on value

Hi there,

I've seen that there are some vaguely familiar posts to this but I haven't been able to find any that answer this precise question.

I'm trying to change the font depending on the cell value automatically using formula rather than the manual insert symbol option (in office 2007 for example), e.g attached.

I understand that this could be done more easily however the symbols I require need to use 3 different fonts. Perhaps instead there is a way of creating my own font which combines the individual characters I need?

Any help would be much appreciated