在运行时更改Crystal Reports组标题字段

I have a Crystal Reports 2008 report that has fields e.g Sector,Branch, Department and a bunch of other fields.The requirement is that the same report should be able to allow grouping by Sector,Branch or Department.I'm trying to avoid creating the same report 3 times with the only difference being the Group Header field.My question is if there is a way to dynamically change the group header at runtime.I have a Crystal Reports 2008 report that has f