CPYF FROMKEY/TOKEY with packed-numeric key

Anybody got a more elegant solution for using CPYF FROMKEY/TOKEY when the
key is packed-numeric?

I had a situation where I thought using INCREL would be satisfactory but,
while it seemed that the key was used to limit the records accessed when run
interactively, it was a total dog in batch as it read through the entire
11,000,000 records.

So I switched to using the FROMKEY/TOKEY.  On a command line, or hard-coded,
it's fairly easy to specify a hex value (i.e. x'020050101F'), but it's
rather kludgy to do when the value is variable.  (Have to set the command
string up in a string variable, and run it via qcmdexc.)  Here's what I
ended up doing, and hoping someone can offer an easier way.

  Dcl  &YearBegin   *dec   (    8   ) Value( 20050101 )
  Dcl  &YearEnd     *dec   (    8   ) Value( 20051231 )
  Dcl  &@YearBegin  *char  (    8   )
  Dcl  &@YearEnd    *char  (    8   )
  Dcl  &Command     *char  ( 1024   ) Value( ' ' )
  Dcl  &CommandLen  *dec   (   15 5 ) Value( 1024 )

  ChgVar     &@YearBegin  &YearBegin
  ChgVar     &@YearEnd    &YearEnd
  ChgVar     &Command  Value( +
               'Cpyf FromFile( CUSMAL06 )  ToFile( *Print ) +
                 FromKey( 1 ( x''0' *cat &@YearBegin *cat 'F'' )) +
                   ToKey( 1 ( x''0' *cat &@YearEnd   *cat 'F'' )) ' )
  SndPgmMsg  ( 'qCmdExc: ' *cat &Command )
  Call       qCmdExc  Parm( &Command &CommandLen )

TIA,
Dan