Private Sub cmdReduceData_Click(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles cmdReduceData.Click
        Dim str_red, wb_RecordSet, wb_result As String
        Dim wb_Search As New System.text.StringBuilder
        Dim wb_array1() As String
        Dim wb_array2() As String
        Dim wb_prodinfo As String
        Dim i, wb_i As Integer
        Dim wb_reg As Regex
 
        Dim StringWork1 As New StringWork
        Me.ds2 = New DataSet
        Dim dt As DataTable = ds1.Tables("CSV")
        Dim dt2 As DataTable = ds2.Tables.Add("Reduziert")
        dt2.Columns.Add("Bezeichnung")
        Dim dr As DataRow
        Dim dr2 As DataRow
 
 
        For i = 0 To dt.Rows.Count - 1
 
            dr = dt.Rows(i)
            str_red = dr("F2")
            wb_prodinfo = str_red.ToUpper
            str_red = Nothing
 
            Dim wb_sr As New StreamReader("c:\WorkBook.txt")
            wb_RecordSet = wb_sr.ReadLine()
            Do While Not IsNothing(wb_RecordSet)
                wb_array1 = Split(wb_RecordSet, ";")
                wb_array1(0) = wb_array1(0).Replace(Chr(34), "")
                wb_array2 = Split(wb_array1(0), "|")
 
                wb_RecordSet = wb_sr.ReadLine()
 
                For wb_i = 0 To wb_array2.Length - 1
                    wb_reg = New Regex(wb_array2(wb_i))
                    If wb_reg.IsMatch(wb_prodinfo) Then
                        For Each m As Match In wb_reg.Matches(wb_prodinfo)
                            If wb_array1(2) <> "" Then
                                Select Case wb_array1(2)
                                    Case 1
                                        wb_result = StringWork1.getNumerics( _
                                          m.Value)
                                        wb_Search = wb_Search.Append(wb_array1( _
                                        1) & wb_result & Chr(32))
                                    Case 2
                                        wb_result = StringWork1.getNumerics( _
                                          m.Value)
                                        wb_Search = wb_Search.Append(wb_result _
                                        & wb_array1(1) & Chr(32))
                                    Case 3
                                        wb_result = StringWork1.CalcMHZ(m.Value)
                                        wb_Search = wb_Search.Append(wb_result _
                                          & wb_array1(1) & Chr(32))
                                End Select
                            Else
                                wb_result = " "
                            End If
 
                            Exit For
                        Next
                    End If
                    If wb_result <> "" Then
                        Exit For
                    End If
                Next
                wb_result = ""
            Loop
            wb_sr.Close()
 
            str_red = dr("F1") & Chr(32) & wb_Search.ToString
            dr2 = dt2.NewRow()
            dr2("Bezeichnung") = str_red
            dt2.Rows.Add(dr2)
 
            wb_Search.Remove(1, wb_Search.Length - 1)
            wb_result = ""
        Next
 
        ds2.AcceptChanges()
 
        'For Each dr In dt.Rows
        'MsgBox(dr("F2"))
        'Next
        DataGrid2.DataSource = ds2.Tables("Reduziert")
 
    End Sub

Nichts ist umsonst!