R: Alternate ways to extract a substring?

[r]

sorry, must control the length

Function Mid2( _
sString As String, _
lStart As Long, _
Optional lLength As Long) As String

If Len(sString) < lStart + 1 Then
Mid2 = Right(sString, Len(sString) + 1 - lStart)
If lLength > Len(Mid2) Then
Mid2 = Left(Mid2, lLength)
End If
End If
End Function

regards
r