Sub CutAfterSubstring()

  Dim dblPosition, dblLength As Double
  Dim strToFind, strLookIn, strResult As String

  'Record the value in the active cell.
  strLookIn = ActiveCell.Value

  'Get the string to search for and determine its length.
  strToFind = InputBox("Cut after which characters?")
  dblLength = Len(strToFind)

  'Find the string within the cell.
  dblPosition = Application.WorksheetFunction.Find(strToFind,   strLookIn)

  'Assign the characters up to the break to a new string.
  strResult = Left(strLookIn, dblPosition + dblLength - 1)

  'Assign the string to the active cell.
  ActiveCell.Value = strResult

End Sub