I have never had success sending graphic reports to a file and then using the file as a fax document. The best solution I have found is to use a third party product like WinFax Pro to capture the output from the report and fax it immediately or to save it in a graphic file that can be faxed later. Another approach is to use the product FoxWord. This software will capture graphic reports from the printer port and save them as RTF files that can be view by many word processors. FoxWord can be downloaded from this site.
Also check you fax server software for a driver that will capture output from the printer port for faxing.
I hope this has given you some ideas.