FRS Report - Line break after change of cost centre in cost centre / parent rows - how?

Summary:

FRS Report - Line break after change of cost centre in cost centre / parent rows - how?

Content (required):

This feels like it should be easy, but isn't proving so.

I have a report with this in the rows; -

First Column:

Descendants of Current Point of View for Cost Centre (Inclusive)

Second Column:

Descendants of IETT (Inclusive)

What I want is a line break after every change in cost centre. I know I can easily put an underline or larger font for the last cost centre by applying a conditional format for when account member (second column) = IETT, but cannot think of a way to have the cost centre and accounts occupying two rows and suppress the second row when <> IETT, is there a way to do this or its equivalent without resorting to explicit cost centres in the first column??