Graham,
Why the loop?
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
Set oCC = ActiveDocument.SelectContentControlsByTitle(strCCName).Item(1)
oCC.LockContentControl = True
oTemplate.AutoTextEntries(strAutotext).Insert Where:=oCC.Range, RichText:=True
lbl_Exit:
Exit Sub
End Sub