How to display a Text that's in a formula on the first Page only?

Hello

  I have a report that has

report header

page header

Group header #1 a, on this (group header # 1a) it's grouping by a customer no and on this group i have a formula which has some text(it's a letter) and I display the letter then below the letter I have

Group Header #2 a. where I display one line that has an address information then

Group Header #2 b. this has the header information things like, invoice_no,invoice_date,amount, currency. then

Group Header #3. this has the currency(no show) then

Group Header #4. this display the currency code either, USD or CHF or EUR then below this is

the Details : this has the detail of what is on Group Header #2 b, the, invoice_no,invoice_date,amount,currency then I have

Group footer #4

Group footer #3: this is the currency where I have a total by currency

Group footer #2

Group footer #1 : this is the customer no

Now the question, sometimes I may have a lot of records(invoices) to be display on the detail and this may run into 2,3 may be 4 pages, how can I display the Text(letter) that's on group header #1 only on the first ?

Thank you