as Bernhard Hiller sayed, some more Info would be great!
but from that what i guessed, shouldn't a simple
Dim myString As String = "ALSDJAHSLDJhp4uihapofjsfd"
myString = myString.Replace("ALSDJAHSLDJ", Nothing)
-> myString ->> hp4uihapofjsfd
just do your thing?