Hi,
Try the code snippet from the below link. It will help you to upload excel file(*.xsl) into SAP CRM.
Its working fine, customize it as you need.
http://wiki.sdn.sap.com/wiki/display/Snippets/ABAP+-+Upload+data+from+Excel+to+Sap+using+OO
Thank you.
Regards,
Swadini Sujanaranjan.