MID(SEXP,IEXP1,IEXP2) (STRING)

 Function
  Get any sub string of a string.

 Syntax
  MID(str,pos,chars)

   str   = A string expression to take the left most characters of.
   pos   = An integer expression with the position within str to start
           taking the sub string from.
   chars = An integer expression with the number of characters to take
           from str.

 Return Type & Value
  STRING
  Returns a string with the specified number of characters from the
  specified position of str.

 Remarks
  This function will return a sub string with the specified number of
  characters and from the specified position of str.  This can be useful
  in data processing as well as text formatting.  The pos parameter may be
  less than 1 (the beginning of the str) and greater than the length of
  str; if it is then spaces will be added to the beginning and/or ending
  as needed.  If chars is less than or equal to 0 then the returned string
  will be empty.  If chars is greater than the available length of str then
  the returned string will have spaces added to the end(s) to pad it out to
  the full length specified.

 Examples
  WHILE (RANDOM(250) <> 0) PRINT MID(RANDOM(250),0,4)," "

  STRING s
  FOPEN 1,"DATA.TXT",O_RD,S_DN
  WHILE (!FERR(1)) DO
    FGET 1,s
    PRINT LEFT(s,5),RTRIM(MID(s,5,20)," ")," - "
    PRINTLN RTRIM(MID(s,LEN(s)-25,60)," ")
  ENDWHILE
  FCLOSE 1