Export Records can export data to a file of type .txt. There are several options, in fact that can produce a file of that type and extension: Merge, CSV and Tab.
But each of these put delimiters, either commas or tabs between different fields of the same records specified in the export so this may create an issue to solve for getting the results that you want.
And you can use Export Field contents to export the contents of a single field to a text file so that may also be an option to consider.
And I've seen mention of a plug in that allows a script to repeatedly write data to the same file, appending the new data to that already found in the file...
That does sound like it will work since I'll need to write to a new file every time I use this option, though I only need to export a few fields at a time. Does the export field option let me move only 3 fields?