Open document / Auto. launch macro to capture text / Auto. modifications to text

[sb003848]

I have a Word document that when opened, a MessageBox is shown asking to insert a text.

Once the text is added to the TextBox (TextBox1), the user could either click on OK (to continue) or cancel (well, to cancel).

If the user clicks on OK, I would like to have the text modified to change ' into ’ and then have the new text pasted (not sure if that is even a word) into the active document. This is what I have so far:
Sub CommandButton1_Click()

Unload Me
End Sub

Any ideas on what I need to add to make that happen?