Hi millot.marius,
Could you please try the following script?:
////////////////////////////////////////////////////
nl=page.nlayers; //number of sheets
iw$=%H; //Input wkbook
Menu -e 34024; //Create an Excel wkbook
ox$=%H; //output wkbook
for(ii=1; ii<=nl; ii++) {
window -a %(iw$); //Activate input wkbook
wrcopy iw:=[%(iw$)]$(ii)! ow:=[%(ox$)]$(ii); //Copy wksheet
}
////////////////////////////////////////////////////
which creates a new Excel workbook, data copied from the original Origin workbook,
within the Origin project. Then, you can change this Excel workbook as "External" by right-clicking
the title bar, and select Properties (or, by saving the Excel book by right-clicking the title bar,
and choose Save As).
Hope this works.
--Hideo Fujii
OriginLab