Display details of a report horizontally

[Greg]

Can someone explain how to make the IP Addresses in the report details
display horizontally and not vertically while keeping the grouping the same.

Here is the situation:

I have a report, based on a query that groups the site name, then the
element name and the IP addresses affected like so:

Site XYZ
Element ABC
192.168.1.3
192.168.4.5
192.168.12.137
Element DEF
192.168.167.236
192.168.1.17
192.168.1.7
192.168.11.16...etc


I would like for the IP Addresses to be listed horizontally like this:

Site XYZ
Element ABC
192.168.1.3, 192.168.4.5, 192.168.12.137
Element DEF
192.168.167.236, 192.168.1.17, 192.168.1.7, 192.168.11.16...etc

Any suggestions would be greatly appreciated!