This problem has plagued me for years.

Our database is used to keep records that go into our various published books.

My current issue revolves around a database of the statistics concerning several hundreds of towns and cities. One field contains the town's population. Because the correct ordering of the records involves using this number (some smaller towns have the same name and thus must be sorted by population as well) I must keep this field as a "number."

Filemaker will let you display such a field with a thousands separator (x,xxx) but it does not export that comma. If I change the field to text, the comma goes away. If I export the field to excel and add a comma (using the 'number' settings there), any attempt at re-importing into FM (even into a text field) will lose the commas.

Basically I want to export the field as viewed, with the thousand separator. Any suggestions?

Did you check the "Apply current data's formatting to export" (in the lower left corner of the "Specify Field Order for Export" dialog window)? Works for me.

When exporting, you have the option to 'Format output using current layout'. Go to a layout that has the field formatted as desired, and select the 'Format...' checkbox when exporting.