There's really no straightforward way to include points from an outside source. I would recommend creating a "fake" tournament and adding the points that way. It's a completely manual process, but this should allow points from an external source to show up in your stats:
1) Create a new tournament. Add 2 players to the tournament (non-database players; just create brand new players on the Players tab and DON'T add them to your database).
2) Start the tournament and have one of the players bust the other out. The tournament is now over.
3) Add to the tournament (from your database) all of the players to which you will be adding points, but DON'T buy them into the tournament.
4) Edit each of those players and in the "Points" section, set the number of points you wish to add for that player in the "Points adjustment" field
5) When you've done this for all players, save the tournament
Now when you run statistics, this tournament should be included (if I remember correctly). Since the actual players in the tournament are not in your database, and the players who ARE in your database are not actually bought into the tournament, no one's statistics should be altered. However, the Points adjustment WILL be included in the statistics calculations (you don't have to be bought-in to have those included; this was done to allow penalizing players who don't show up for a tournament in which they pre-registered or pre-affirmed).
I hope this does what you are looking for.