Try the following saved in the normal template (which is normal.dotm, not normal.dotx).
The normal template must also have the named style
The message boxes are there for information only while testing. They can be removed along with the 'Else' branch of the conditional statement.
New documents based on the normal template will have the style.
Sub AutoOpen()
Dim strMyStyle As String
Dim oStyle As Style
Dim bFound As Boolean
strMyStyle = "MorzNum"
For Each oStyle In ActiveDocument.Styles
If oStyle.NameLocal = strMyStyle Then
bFound = True
Exit For
End If
Next oStyle
If Not bFound = True Then
MsgBox strMyStyle & " Style added to the document"
Application.OrganizerCopy _
Source:=ThisDocument.FullName, _
Destination:=ActiveDocument.FullName, _
Name:=strMyStyle, _
Object:=wdOrganizerObjectStyles
Else
MsgBox "The style " & strMyStyle & " already exists in the document "
End If
End Sub