Hi, Olivier:
You'll have to check with Tech Support for sure, but I have always thought that those options belonged to /worked with ODS PRINTER family destinations, only -- sort of like PAPERSOURCE, DUPLEX etc are only ODS PRINTER options. I thought that PAPERSIZE and PAPERDEST, et al were for PRINTING from the LOG, the LISTING window or some ODS PRINTER destinations. (They belong to a category called ODSPRINT.)
Since ExcelXP is a MARKUP destination, those options would not have an effect on Excel -- since they are SAS options. If you can figure out what XML tags need to be specified so Excel will use different values, then you could change the ExcelXP tagset to use those values.
cynthia