Exporting in MS Word format

Does anybody know if there is a way to force LBI to save exported documents in either .doc or .docx format instead of .rtf format when choosing Microsoft Word (editable) as the export format option?

When exporting the documents, even though choosing MS Word a the export format, the file type that it saves the file as is actually .RTF instead of either .doc or preferably .docx. We have been asked to use .doc/.docx because the documents saved in .rtf file format take up so much more space than .doc/.docx documents do.

Thanks.