question about "unknown DS name 'PrinterTonerCartrid'"

I deciced to change my status line from

        Printer Cartridge Counter = $SNMPTONERCOUNTER
to 
        Printer Toner Cartridge Counter = $SNMPTONERCOUNTER

and started getting the dreaded error "unknown DS name 'PrinterTonerCartrid'

Q1) Is is possible to dump the file edit the name from 'PrinterCartridgeCo' to 'PrinterTonerCartrid' and the restore?

My status line look as follows:


       LINE="status $TARGETHOST.Prn $COLOR `date`
        
        Printer Counter = $SNMPPAGECOUNTER
        Printer Cartridge Counter = $SNMPTONERCOUNTER
        Total Pages Printed Since $SINCE When We Started Counting = $PAGESPRINTED
        Delta Pages Printed = $DELTAPAGESPRINTED


"
All I want to plot is the Delta Pages Printer = line. 

Q2) Is there a way to tell rrd to ignore other lines that I added to the status?

Thanks

Robert

Robert P. McGraw, Jr.
Manager, Computer System                    EMAIL: user-33cf07af04dd@xymon.invalid
Purdue University                            ROOM: MATH-807
Department of Mathematics                   PHONE: (XXX) XXX-XXXX
XXX N. University Street                      
West Lafayette, IN XXXXX-XXXX