VB.Net VSTO PowerPoint Addin

I'm making an Add-in for PowerPoint 2013. My goal is to convert all equations that I find on slides to normal text, to change the font of those equations. Because it won't let me change font while they are equations. I managed to find the equations, by iterating through text ranges and finding font name, they use "Cambria Math". So my question is how can programmatically change equations to normal text, Like the button in equation tools does? And it seems for some reason they removed "record macro" from PowerPoint, so I couldn't get help from that. I tried recording macro in word and doing the same thing, and i got: Selection.OMaths(1).ConvertToMathText, but it doesn't seem to be OMaths in PowerPoint.

Dim Application As PowerPoint.Application = New PowerPoint.Application
        Dim Presentation As PowerPoint.Presentation = Application.ActivePresentation
        Dim Windows As PowerPoint.DocumentWindows = Application.Windows

        For Each Slide As PowerPoint.Slide In Presentation.Slides
            For Each Shape As PowerPoint.Shape In Slide.Shapes
                For Each Paragraph As PowerPoint.TextRange In Shape.TextFrame.TextRange
                    For Each Line As PowerPoint.TextRange In Paragraph.Lines
                        If Line.Font.Name = "Cambria Math" Then
                            With Line.Font
                                .Name = "Calibri"
                                .Bold = True
                            End With
                        ElseIf Line.Font.Name = "Calibri" Then
                            With Line.Font
                                .Name = "Palatino"
                            End With
                        End If
                    Next Line
                Next Paragraph
            Next Shape
            Next Slide
    End Sub

Other text here is changed normally, but equations the ones with "Math Cambria" font, are unchanged.

I also tried to get selection, then something with OMaths, like in Word Vsto, but, it seems OMaths is not part of the PowerPoint. This next code is actually supposed to change it to equation, but i guess if it worked, could have find a way to reverse it.

For Each Window As PowerPoint.DocumentWindow In Windows
    Selection.OMaths(1).ConvertToMathText
Next Window

I got it to work with PowerPoint 2016 in VBA. I didn't have "Calibri" in my list of fonts, so I changed it to "Calibri (Body)" and it works. It may be the same issue you're having with the .NET VSTO Addin. If I have time, I'll build a example of the VSTO Addin and post the results as well.

Video

VBA Code

Public Sub UpdateShapeFont()
On Error GoTo ErrTrap
Dim Application     As PowerPoint.Application: Set Application = New PowerPoint.Application
Dim Presentation    As PowerPoint.Presentation: Set Presentation = Application.ActivePresentation
Dim Windows         As PowerPoint.DocumentWindows: Set Windows = Application.Windows
Dim Slide           As PowerPoint.Slide
Dim Shape           As PowerPoint.Shape
Dim Paragraph       As PowerPoint.TextRange
Dim line            As PowerPoint.TextRange

    For Each Slide In Presentation.Slides
        For Each Shape In Slide.Shapes
            For Each Paragraph In Shape.TextFrame.TextRange
                For Each line In Paragraph.Lines
                    Select Case line.Font.Name
                        Case "Cambria Math"
                            With line.Font
                                .Name = "Calibri (Body)" 'check if the font exists in your list of fonts; it did not work for "Calibri"
                                .Bold = True
                            End With
                        Case "Calibri"
                            With line.Font
                                .Name = "Palatino"
                            End With
                    End Select
                Next line
            Next Paragraph
        Next Shape
    Next Slide
            
ExitProcedure:
    On Error Resume Next
    Exit Sub

ErrTrap:
    Select Case Err.number
        Case Else
            Debug.Print "Error #: " & Err.number & " |Error Description: " & Err.description
    End Select
    Resume ExitProcedure
    Resume 'for debugging
    
End Sub