Find the rightmost character ('/') on an address link

Hi everyone.  I checked on the archives in regards to data manipulation but I
was not successful.  Again, you help.

I am reading a file that contains links to specific engineering drawing images
in the servers.

For example, I have a link like this:
NPR-SERVER-NT/SCANNING/Common/Steve%20Maher/EAR90881/AC9012F1240Y6.B.HPGL

I need to just get the file name only.  However, I am trying to use the CHECKR
and CHECK commands to "surround" the file name but apparently I can't make it to
work.

(DRLINK is 256 char long:)

'/'           Checkr    drlink        DashPos
' '           Check     drlink        BlankPos
              Eval      Link_File_Name =
                        %subst(drlink:
                        DashPos + 1:
                        (BlankPos - 1) - DashPos)

The results are:
DSAHPOS = 256
BLANKPOS = 1

I am pretty sure that I am doing something wrong... HELP!

TIA!

Peter Vidal
Programmer Analyst
PALL Aeropower Corp.