Hello Ted,
Instead of displaying Column headers in a Text field create a formula and display the Column name in that formula and use that formula to display Column header in report this will not trim your column header when you export that in excel.
Say for e.g. you are displaying Column header as "Number of Passengers" in a text field on report so instead of that create a formula with definition @Formula1 as "Number of Passengers" and use this formula in your report.
Let me know if this helps.
Regards
Niraj
