Public Function StrBetween(Cadena As String, SubCadena1 As String, Subcadena2 As String) As String
Dim Pos1 As Integer, Pos2 As Integer
Pos1 = InStr(UCase(Cadena), UCase(SubCadena1)) + 1
Pos2 = InStr(UCase(Cadena), UCase(Subcadena2))
If Pos1 <> 0 And Pos2 <> 0 Then
StrBetween = Mid$(Cadena, Pos1, Pos2 - Pos1)
End If
End Function
Private Sub Form_Load()
Dim ASd As String
Dim Asd2 As String
ASd = "aitheoiethi[BLABLABLAkjhuihui]taihoithaoihtoea"
Asd2 = StrBetween(ASd, "[", "]")
MsgBox Asd2
End Sub
Por hay tambien hay una funcion que hizo Psyke1, espero que te sirva...