CAD tip # 8718:

You can use the following simple iLogic macro - when run, it creates/updates the location of the MyCOG workpoint in the model document:

Dim cogName As String = "MyCOG"

Dim doc As Document = ThisDoc.Document

Dim cog As WorkPoint
Try
 cog = doc.ComponentDefinition.WorkPoints(cogName)
 cog.SetFixed(doc.ComponentDefinition.MassProperties.CenterOfMass)
Catch
 cog = doc.ComponentDefinition.WorkPoints.AddFixed(doc.ComponentDefinition.MassProperties.CenterOfMass)
 cog.Name = cogName
End Try