Change listbox value

[Excel Fox]

This should help. I've added textboxes to a second userform during run time when you click on one row in the first userform.

Here's the code for reference

Public var As Variant
Dim rng As Range
Private Sub ListBox1_Click()

    UserForm2.Show 0
    
End Sub

Private Sub UserForm_Initialize()

    With ListBox1
        Set rng = Worksheets(Replace(Split(.RowSource, "!")(0), "'", "")).Range(Split(.RowSource, "!")(1))
'If your row source doesn't have reference to a sheet, but only to a range, just use Set rng = Range(RowSource)
    var = rng
        .RowSource = ""
        .List = var
    End With
    
End Sub

Private Sub UserForm_Terminate()

    rng.Value = var
    
End Sub

Dim txtSampleTextBox() As MSForms.TextBox
Private Sub UserForm_Initialize()
    
    Dim lng As Long
    Dim obj As MSForms.TextBox
    lng = UserForm1.ListBox1.ColumnCount
    ReDim Preserve txtSampleTextBox(1 To lng)
    
    For lng = 1 To lng
        Set txtSampleTextBox(lng) = Controls.Add("Forms.TextBox.1", "txtSampleTextBox" & lng)
        With txtSampleTextBox(lng)
            .Left = (lng - 1) * .Width + 5
            .Text = UserForm1.ListBox1.List(UserForm1.ListBox1.ListIndex, lng - 1)
        End With
    Next lng
    Me.Width = (lng - 1) * (txtSampleTextBox(lng - 1).Width + 1)

End Sub

Private Sub UserForm_QueryClose(Cancel As Integer, CloseMode As Integer)

    Dim lng As Long
    With UserForm1.ListBox1
        For lng = 1 To Me.Controls.Count
            .List(.ListIndex, lng - 1) = Controls("txtSampleTextBox" & lng).Text
        Next lng
        UserForm1.var = .List
    End With
    
End Sub