Hi David,
Thanks for your interest in Syncfusion Products.
In a GridGroupingControl, the display order of the columns in the grid is determined by the grid.TableDescriptor.VisibleColumnsCollection. Changing the order of the columns in this collection will change the display order on the screen. Please refer to the code snippet.
this.gridGroupingControl1.TableDescriptor.VisibleColumns.Move(source, destination);
Here is a small sample:
http://files.syncfusion.com/samples/Grid.Windows/GGC_MoveColumns.zipLet me know if this serve your needs.
Regards,
Nisha.