How to automatically paste text to cursor site within text entered into a UserForm textbox?

My user needs to type freehand notes into an Excel UserForm textbox control. But this requires the accurate spelling of some words that are easy to mis-spell, and accuracy is required.  So, at the side of the Userform, I can provide the user with a list of these 'tedious' spellings, each in the form of caption text in a UserForm label control.

In the model below, I can replace text in UserForm textbox with new copied text, or I can append new copied text to existing text. But:

MY QUESTION: how do I inset the copied text into existing text at a position marked by the Cursor in the text box?

MY MODEL (attached file):
When the user clicks a label control (in code below ctl.name = "Label1" ) its caption text is copied to clipboard:

Private MyData As New DataObject

Private Sub Label1_Click()
    MsgBox "Copy active in Label1_Click()" 'visual check that click event works
    MyData.SetText Label1.Caption
    MyData.PutInClipboard
End Sub

This pastes copied text into textbox1:

Private Sub pasteText_Click()
    TextBox1.Text = MyData.GetText
End Sub

I can append the copied text to existing text in texBox1 by:
TextBox1.Text = TextBox1.Text & " " & MyData.GetText

Thanks
Kelvin4
Paste2TextBox.xlsm