Can you force libreoffice to open files with calc over the UNO bridge?

I’m using unoconv + libreoffice to convert spreadsheets to CSVs.
Sometimes the libreoffice autodetection won’t work quite right and libreoffice will open files with the text editor instead of calc. (This is the case of malformed .xls files that either have HTML or CSV text data inside).

Is there anyway to make libreoffice open the documents with calc?

For a file I had, I was able to get it to convert correctly by setting the FilterName to ‘HTML (StarCalc)’ – but not all the files I want to convert will be that. Can I specify all the calc filters at once? Or how do I make it just use calc?