>I might be wrong, but I thought there was a tool that allows importing XLS files without having Excel installed?
Do you mean XLS or XLSX?
For XLS you can use command IMPORT or APPEND.
For XLSX or XLS you can use ODBC or OLE-DB driver.
For XLSX you can use this utility:
http://praisachion.blogspot.com/2015/06/append-from-xlsx.htmlMartinaJ
