Conditional formatting in relation to a target

Hi,

A while ago some guys on here helped me create a teacher's markbook which I thought was perfect until my head of department has listed some new criteria.

I've attached the current mark book which is functioning perfectly.

The new requirement is that rather than assessing 1 topic at each assessment, we'll assess 2; the topic studied and the topic previous to that.

So, the assessments will be:

Unit 1
Unit 1 & 2
Unit 2 & 3
Unit 3 & 4
Unit 4 & 5

The grade boundaries will remain the same (as per the lookup table) so I just need a way of adding in the extra units and dividing the combined score in 2. That combined score needs to then be compared to their target grade to give an overall indication about whether they're above below or on target.

I've attached a new version of what I'd like the workbook to look like but since I've added all the new columns, all the functionality is lost. I don't know whether it's easier to work on the original adding a column at a time or if there's a way of copying over the formulas to the new workbook.

I've been amazed by the help so far and would be eternally grateful if you could help me finish the job.........