Issues trying to understand a HTBasic code

  IF Y$="" THEN
      REPEAT
          INPUT "FILE NAME**strong text** ?",Y$
          Y$=TRIM$(Y$)
      UNTIL LEN(Y$)<8
  END IF

  DISP "enr "&Ld$&"\";Y$
  Nb_rc=VAL(Mesu$(0,5))+1
  ON ERROR CALL Ges_err
  CREATE BDAT Y$&"t",VAL(Mesu$(0,5))+2,7*34
      1   ASSIGN @Voie_0 TO Y$&"t"
      2   OUTPUT @Voie_0;Mesu$(*)
      3   ASSIGN @Voie_0 TO *
  CREATE BDAT Y$&"v",VAL(Mesu$(0,6)),(VAL(Mesu$(0,5))+1)*8
  ASSIGN @Voie_0 TO Y$&"v"
  OUTPUT @Voie_0;V(*)
  ASSIGN @Voie_0 TO *
  OFF ERROR
  RETURN

Here is some HTBasic code, I'm not able to understand what those lines (1,2,3) do.

I found out what those lines mean.

Line 1  : Assign the Path of a file in a "Global variable" named @Voie_0
Line 2  : Writing the values of the tab Mesu in the file 
Line 3  : Clear the global variable