Both of these are covered in the online documentation. These instructions are for a Mac, but should be similar to the PC version.Create an ossia measure (preferred method):
1) create an extra staff;
2) put the notes you want for the ossia measure in the extra staff (at the same measure number is convenient);
3) click the ossia tool, then click the measure to which you would like the ossia measure to belong;
4) in the dialogue box that comes up, select your options;
5) click the staff tool, then double click the box above the clef of the new staff you created; in the dialogue box that opens, check the "Hide Staff" box.
Export Selection:
1) in Page View, with the graphic tool selected, double click and drag across the region you want to make into a graphic;
2) select "Export Selection" from the graphics menu.
If you do not have the online documentation on your hard drive (an option for those with limited hard drive space), you can find it on your Finale CD. Look for the "Ossia Tool.pdf" file.