Crystal Reports: How to suppress group header based on formula in footer

We have a report that includes variables to calculate an adjusted total.
The problem we have is that we need to suppress a group header where the value of a formula (including a variable) in the group footer is zero.

The setup of the report is as follows:

In a group header (Group 1 - Employee) is the folllowing formula called Declare Achieved Target:

WhilePrintingRecords;
NumberVar AchievedTotal;
if not InRepeatedGroupHeader then
AchievedTotal := 0
else if InRepeatedGroupHeader then
AchievedTotal := AchievedTotal



Then in the next group header (Group 2 -Competency) is the following formula called Calc Achieved Target:

WhilePrintingRecords;
NumberVar AchievedTotal;
AchievedTotal := AchievedTotal + {@Adjusted Achieved}


Then in the footer for Group 1 (Employee) is the following formula called Display Achieved Target:

WhilePrintingRecords;
NumberVar AchievedTotal;
AchievedTotal;

What we need to have happen is that if the value of the 'Display Achieved Target' is zero the Group header and group footer for Group 1 Employee need to be suppressed.

We can suppress the footer record by including the following in the suppress option against the footer

If {@Display Gap} = 0 then true else false

But this doesnt work for the header. I understand that this is because of the order in which Crystal processes but we need to find a way of suppresses the header row?

Any ideas if this can be done? We are using Crystal Reports v9.

thanks