Использование формул в ячейках DataGridView

Public Class Form1
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        DGV.Rows.Add("2+2")
        DGV.Rows.Add("2+2*(3+7)")
    End Sub
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim obj = CreateObject("MSScriptControl.ScriptControl") : obj.Language = "VBScript"
        For Each row As DataGridViewRow In DGV.Rows
            Try
                row.Cells(1).Value = Val(obj.Eval(row.Cells(0).Value))
            Catch ex As Exception
                row.Cells(1).Value = "#ошибка"
            End Try
        Next
    End Sub
End Class

If строка.StartWith("A") Then ...

 Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        DataGridView1.ColumnCount = 3
        DataGridView1.Columns(0).Name = "K1"
        DataGridView1.Columns(1).Name = "K2"
        DataGridView1.Columns(2).Name = "Itog"
 
        Dim row As String() = New String() {"1", "2", "3"}
        DataGridView1.Rows.Add(row)
        row = New String() {"42", "43", "44"}
        DataGridView1.Rows.Add(row)
        row = New String() {"45", "46", "7"}
        DataGridView1.Rows.Add(row)
        row = New String() {"48", "49", "50"}
        DataGridView1.Rows.Add(row)
    End Sub
    Private Sub DataGridView1_CellEndEdit(sender As Object, e As DataGridViewCellEventArgs) Handles DataGridView1.CellEndEdit
        Dim InvoiceDetails As DataGridView = DirectCast(sender, DataGridView)
        If IsDBNull(InvoiceDetails(0, e.RowIndex).Value) Then Exit Sub
        InvoiceDetails("Itog", e.RowIndex).Value = InvoiceDetails("K2", e.RowIndex).Value * InvoiceDetails("K1", e.RowIndex).Value
        If (e.ColumnIndex = 2 Or e.ColumnIndex = 3) And InvoiceDetails.Rows.Count > 0 Then
            TextBox1.Text = Total().ToString
        End If
    End Sub
    Private Function Total() As Double
        Dim tot As Double = 0
        Dim i As Integer = 0
        For i = 0 To InvoiceDetailsDataGridView.Rows.Count - 1
            tot = tot + Convert.ToDouble(InvoiceDetailsDataGridView.Rows(i).Cells("Itog").Value)
        Next i
        Return tot
    End Function
    Private Function InvoiceDetailsDataGridView() As Object
        Throw New NotImplementedException
    End Function

    Dim FirstValue, SecondValue As Object
Dim ri,  ci As Integer
Private Sub MainDataGrid_CellEndEdit(sender As Object, e As DataGridViewCellEventArgs) Handles MainDataGrid.CellEndEdit
        If MainDataGrid.CurrentCell.ColumnIndex = 4 Or MainDataGrid.CurrentCell.ColumnIndex = 5 Then
            ri = MainDataGrid.CurrentCell.RowIndex
            ci = MainDataGrid.CurrentCell.ColumnIndex
            If Strings.Left(MainDataGrid.CurrentCell.Value, 1) = "=" Then MainDataGrid.CurrentCell.Value = MainDataGrid.CurrentCell.Value.Replace(Strings.Left(MainDataGrid.CurrentCell.Value, 1), "")
            Dim obj = CreateObject("MSScriptControl.ScriptControl") : obj.Language = "VBScript"
            FirstValue = MainDataGrid.CurrentCell.Value
            DataGridAssister(ci - 4, ri).Value = FirstValue
            For Each row As DataGridViewRow In MainDataGrid.Rows
                Try
                    MainDataGrid.CurrentCell.Value = Val(obj.Eval(MainDataGrid.CurrentCell.Value))
                    SecondValue = MainDataGrid.CurrentCell.Value
                Catch ex As Exception
                    If MsgBox("Текст ошибки", MsgBoxStyle.Critical, "Заголовок ошибки") = MsgBoxResult.Ok Then
                        FirstValue = Nothing
                        Exit For
                    End If
                End Try
            Next
        End If
    End Sub
    Private Sub MainDataGrid_CellBeginEdit(sender As Object, e As DataGridViewCellCancelEventArgs) Handles MainDataGrid.CellBeginEdit
        If MainDataGrid.CurrentCell.ColumnIndex = 4 Or MainDataGrid.CurrentCell.ColumnIndex = 5 Then
            ri = MainDataGrid.CurrentCell.RowIndex
            ci = MainDataGrid.CurrentCell.ColumnIndex
            If MainDataGrid.CurrentCell.Value = Nothing Then DataGridAssister(ci - 4, ri).Value = Nothing
            If MainDataGrid.CurrentCell.Selected = True Then MainDataGrid.CurrentCell.Value = DataGridAssister(ci - 4, ri).Value
            End If
    End Sub