Sorry about the late reply, my site has been a round for many years and your the first to post anything, I'm a little shocked to be honest, thank you.

Great question, in later revisions of CATIA they did indeed add AxisSystem to the EKL datum objects. I have not tried to create a Datum Axis Systema and then convert it to a Parametric one, but an Axis System is not a geometrical element behind the scenes its a parameter.  I know this is odd but pre-CATIA V5 R14 all geometrical objects were parameters not geometry types.  For what ever reason Axis Systems didn't get converted.

So this is how to convert a point.

// ConvertDatumPointtoPointCoord( iPoint : Point ) : Void

Let oGSMPoint ( GSMPoint )
Set oGSMPoint = iPoint
oGSMPoint.PointType =  "Coordinates"
  
Let oGSMPointCoord( GSMPointCoord )
Set oGSMPointCoord = oGSMPoint
oGSMPointCoord.X = iPoint->coord(1)
oGSMPointCoord.Y = iPoint->coord(2)
oGSMPointCoord.Z = iPoint->coord(3)

If the API is there in the latest release, and I will check on Monday, I would expect something similar to this.

// ConvertDatumAxisSystem( iAxisSystem : AxisSystem ) : Void

Let oGSMAxisSystem ( GSMAxisSystem)
Set oGSMAxisSystem = iAxisSystem
oGSMAxisSystem.AxisSystemType =  "Standard"

Let oGSMAxisSystemStandard ( GSMAxisSystemStandard )
Set oGSMAxisSystemStandard = oGSMAxisSystem
Set oGSMAxisSystemStandard.X = iAxisSystem.X
Set oGSMAxisSystemStandard.Y = iAxisSystem.Y
Set oGSMAxisSystemStandard.Z = iAxisSystem.Z