The supported way to change the output location is (How To Change The Log And Output Location For Concurrent Managers? (Doc ID 872766.1)) but this won't meet your requirements.
Apart from what others mentioned above, you can write your own code to copy/delete the file using PL/SQL stored procedure.
How To Copy a Text File From One Directory To Another Using Stored Procedure? (Doc ID 317338.1)
Examples : UTL_FILE.FCOPY(), FRENAME(), FREMOVE() and FGETATTR() (Doc ID 196948.1)
Examples : UTL_FILE.FSEEK() and FGETPOS() (Doc ID 196949.1)
you need to change one of profile option
File Format: FO
Mime type: application/vnd.ms-excel
Yes, we can do that using the FND_FILE commands.... I done that and is working well n good
Thankq all for your replies