Code:
Private Sub COG2Sketch()Dim oApp As Inventor.Application
Set oApp = ThisApplication
Dim oDoc As PartDocument
Set oDoc = oApp.ActiveDocument
Dim oCenterOfMass As Point
Set oCenterOfMass = oDoc.ComponentDefinition.MassProperties.CenterOfMass
Dim oSketch As PlanarSketch
Set oSketch = oDoc.ComponentDefinition.Sketches.Item(1)
Dim oPoint As Point2d
Set oPoint = oSketch.ModelToSketchSpace(oCenterOfMass)
End Sub