How to phase Player by Quest

[Corelith]

Trying to phase a player with a custom quest, but don't realy find any tutorial in the wides of web...

Background: I made a custom quest with NPCs and all around - and it works (or most of it...).
Now i'm trying to put my quest-NPCs into another phase... perhaps 16 or what ever (best would be an 'empty phase' - so that there is no other effect for the players...)
I did it just to test with my first questender and put him into phase 16 with ".npc set phase 16".
That worked and ater reload, my playeraccount char didn't see the npc anymore.

Now my issu is, to make the player seeing phase 16 (for example), if he oder she got any quest of my custom questline.
I think it's about questflag 4194304 ( QUEST_FLAGS_UPDATE_PHASE_SHIFT ), but don't know how it works to put there a phase like '16' (in my case now)...

Anyone who could explain?