Split a string into 2 either side a delimiter in FORTRAN

splitstring.f90

  ! split a string into 2 either side of a delimiter token
  SUBROUTINE split_string(instring, string1, string2, delim)
    CHARACTER(30) :: instring,delim
    CHARACTER(30),INTENT(OUT):: string1,string2
    INTEGER :: index

    instring = TRIM(instring)

    index = SCAN(instring,delim)
    string1 = instring(1:index-1)
    string2 = instring(index+1:)

  END SUBROUTINE split_string

What will happen if delimiter spears at position 1?
for example "hello;world" with semicolon as delimiter works, but how about
";hello"

What will happen if delimiter spears at position 1?
for example "hello;world" with semicolon as delimiter works, but how about
";hello"

In my opinion, there is no use to do that in the first place since it beats the role of a delimiter which is to separate data.