Never tried to do this but...
What you could do as part of a custom Switchboard or form that calls the Report is to include code that access the Title Property of the Graph object within the report.
It's the same sort of manipulation that one might do to use one report as a template but to vary the recordsource depending on need. Numerous examples around here on that type of subject.
Look up something like "Report Properties" and browse the object viewer within VBA specifically looking at report properties.
Mike