How can I make a group of controls on a userform, like Option Buttons, an array so that I can use them in a For/Next procedure?

You cannot use control arrays in VBA. Try using the TAG property instead.
In this example there's 4 textboxes and a commandbtn:

Private Sub CommandButton1_Click()
Dim Ctl As Control
Dim i As Integer

For Each Ctl In UserForm1.Controls
    If Not Ctl.Tag = "" Then ' If omitted, all controls in form must have a TAG value
        For i = 1 To 4
            If Ctl.Tag = i Then
                Ctl.BackColor = vbYellow
            End If
        Next
    End If
Next

End Sub

You decide which TAG value a control will have, so make series for your groups and loop in theese ranges.

True, VBA doesn't support control arrays, however you can simulate it quite well by creating a class that acts as a container for the control object.

At run-time you can dynamically create the VBA control (ie. MyForm.Controls.Add("MSForms.OptionButton") ), pass it the resulting control object in to your class, then add the class object to a collection.

You can then iterate using a For..Each loop quite nicely, and obviously group control functionality together.

If you do this, you'd almost certainly want to declare the control WithEvents in your class so that you can expose all the normal control events, such as Click and Change.

Hope that's what you meant, anyway!

Hi gcianfanelli:
your idea is great. Could you please post a sample code for this.

I have several textboxes and several checkboxes in a form in VBA. Based on the user choice, the data has to be transferred to the SS. I have 24 controls and may increase. I like to create a class and use the built in methods of these controls. I really appreciate your code.