tell application "/Applications/Microsoft Word.app"
set myHeader to get header section 1 of active document index header footer first page
make new page number at myHeader with properties {alignment:align page number right}
end tell

tell application "/Applications/Microsoft Word.app"
set myHeader to get header section 1 of active document index header footer primary
make new page number at myHeader with properties {alignment:align page number right}
end tell