Sub ConvertEquation()
Application.ScreenUpdating = False
Dim Rng As Range, objEqn As OMath, Correction As OMathAutoCorrectEntry
Application.OMathAutoCorrect.UseOutsideOMath = True
Set Rng = Selection.Range: If Rng.End = Rng.Paragraphs.First.Range.End Then Rng.End = Rng.End - 1
For Each Correction In Application.OMathAutoCorrect.Entries
  If InStr(Rng.Text, Correction.Name) > 0 Then Rng.Text = Replace(Rng.Text, Correction.Name, Correction.Value)
Next
Rng.OMaths.Add(Rng).OMaths(1).BuildUp
Application.ScreenUpdating = True
End Sub