[oXygen-user] how to change value of attributes

Hi all, i'm a librarian with a problem: i've to change the value of attribute for each element of a group that i'm not able to select and count. i've something like this: <mets:div LABEL="Testo" ORDER="4" ORDERLABEL="1"> <mets:div LABEL="Frontespizio" ORDER="1" ORDERLABEL="1"> <mets:div LABEL="Pagina 5" ORDER="1" ORDERLABEL="5"> <mets:fptr FILEID="file.00008"/> </mets:div> </mets:div> <mets:div LABEL="Dedica" ORDER="2" ORDERLABEL="1"> <mets:div LABEL="Pagina 6" ORDER="1" ORDERLABEL="6"> <mets:fptr FILEID="file.00009"/> </mets:div> </mets:div> <mets:div LABEL="Canto I" ORDER="3" ORDERLABEL="1"> <mets:div LABEL="Pagina 7" ORDER="1" ORDERLABEL="7"> <mets:fptr FILEID="file.00010"/> </mets:div> <mets:div LABEL="Pagina 8" ORDER="2" ORDERLABEL="8"> <mets:fptr FILEID="file.00011"/> </mets:div> <mets:div LABEL="Pagina 9" ORDER="3" ORDERLABEL="9"> <mets:fptr FILEID="file.00012"/> </mets:div> </mets:div> </mets:div> i have to change the value of LABEL from "pagina 5, pagina 6, pagina 7, pagina 8, etc..." to "carta 1r, carta 1v, carta 2r, carta 2v, etc". It will be something like this: <mets:div LABEL="Testo" ORDER="4" ORDERLABEL="1"> <mets:div LABEL="Frontespizio" ORDER="1" ORDERLABEL="1"> <mets:div LABEL="Carta 1r" ORDER="1" ORDERLABEL="5"> <mets:fptr FILEID="file.00008"/> </mets:div> </mets:div> <mets:div LABEL="Dedica" ORDER="2" ORDERLABEL="1"> <mets:div LABEL="Carta 1v" ORDER="1" ORDERLABEL="6"> <mets:fptr FILEID="file.00009"/> </mets:div> </mets:div> <mets:div LABEL="Canto I" ORDER="3" ORDERLABEL="1"> <mets:div LABEL="Carta 2r" ORDER="1" ORDERLABEL="7"> <mets:fptr FILEID="file.00010"/> </mets:div> <mets:div LABEL="Carta 2v" ORDER="2" ORDERLABEL="8"> <mets:fptr FILEID="file.00011"/> </mets:div> <mets:div LABEL="Carta 3r" ORDER="3" ORDERLABEL="9"> <mets:fptr FILEID="file.00012"/> </mets:div> </mets:div> </mets:div> thanks a lot to everyone.