CALL SEXP

 Function
  Call (execute) another PPE file from the currently executing PPE
  using the filename specified by SEXP.

 Syntax
  CALL filename

   filename  - A string expression containing the complete path and
               filename of a PPE file to load and execute.

 Remarks
  It is sometimes convienient to load and run complete programs from
  other programs, similar to how you process subroutines with GOSUB and
  RETURN.  PPL supports running both external EXE and COM files via the
  SHELL statement and other PPE files via the CALL statement.  CALL allows
  you to load and run another PPE file, after which control returns to the
  first PPE at the statement after the CALL.  The second PPE is completely
  separate from the first.  You may pass values to the PPE by tokenizing
  a string with the TOKENIZE statement.  If you need to pass values back
  to the first PPE, you will need to create some sort of parameter passing
  convention yourself.  For example, you may have the second PPE create a
  file that has the needed information for the first PPE.

 Examples
  STRING s
  INPUT "What PPE file do you wish to run",s
  CALL "C:\PCB\PPE\"+s+".PPE"