Power point already open

[wallacej]

I have the following code which opens PowerPoint, creates a presentation, adds a slide and then inserts an image onto the slide:

Private Sub openPowerPoint()
    Dim ppObject As PowerPoint.Application
    Dim ppPres As PowerPoint.Presentation
    Dim picLocation As String
    
    'Open and show PowerPoint
    Set ppObject = New PowerPoint.Application
    ppObject.Visible = True
    
    'Add presentation to PowerPoint
    ppObject.Presentations.Add
    Set ppPres = ppObject.Presentations.Item(1)
   
    'Add a blank slide to PowerPoint presentation
    ppPres.Slides.Add 1, ppLayoutBlank
    ppPres.Slides(1).Select
    
    'Insert picture
    picLocation = txtToInsert.Text
    'size needs to be decided
    ppPres.Slides(1).Shapes.AddPicture(FileName:=picLocation, LinkToFile:=False, SaveWithDocument:=True, Left:=0, Top:=0, Width:=170, Height:=230).Select
 
End Sub

Can anybody help me to perform a similar task but with powerpoint already open?
The code would just have to create a new slide and then insert the image.

Thanks