I often need to open pipe delimited .txt files in LibreOffice Calc. However, once I have Calc running, if I do File > Open and select a spreadsheet with the extension .txt, it opens it in Writer instead.

Is there a way to tell the file I'm trying to open using whatever program instead of trying to pick which one to use?

Barring that, is there a way I tell it to always use Calc for .txt files (when I open them from the open dialog in Calc)? I still want them to open in GEdit like they currently do if I double click them from Thunar.