You could use a simple function to fill a rich text content control with the formatted text from the autotext entry, according to the value selected in the list box (see attached template) e.g. as follows - Create a new document from the template
Code:
Sub AutoTextToCC(strCCName As String, oTemplate As Template, strAutotext As String)
'Graham Mayor - https://www.gmayor.com - Last updated - 10 Apr 2019
'strCCName is the ContentControl title
'oTemplate is the template with the autotext entry
'strAutotext is the name of the autotext entry
Dim oCC As ContentControl
On Error GoTo lbl_Exit
For Each oCC In ActiveDocument.ContentControls
If oCC.TITLE = strCCName Then
oCC.LockContentControl = True
oTemplate.AutoTextEntries(strAutotext).Insert Where:=oCC.Range, RichText:=True
Exit For
End If
Next oCC
lbl_Exit:
Exit Sub
End Sub
You may find
Insert Content Control Add-In useful for entering and/or modifying the content controls.