'Late Activation' Navigation Target Points

[Wrench]

I've seen (and used) the navigation target points you can add in the mission editor for Fix point, Initial Point, etc. I saw that you can add Datalink points (Datalink Waypoint 1 Through 3 DLWP1, DLWP2 and DLWP3) in the manual, and this got me thinking:

Is it possible to add them mid-mission, either through something in the mission editor I've not seen or through script?

I'd like to simulate an actual datalink target being sent in real-time.