Change VLAN to 3999?

Hey :),

So my providers tv box offer working only thru VLAN 3999 and port is "trunk" (video+internet). And due my minix need both video and internet if I want to get iptv on it, is there a way to create/change VLAN 3999 (i guess 3999 is some port or something?)?

I want to avoid providers tv box and use one box for everything.

P.S.:
Before someone falme me, that I have got illegal m3u playlist or something, let me tell you it is not. I can generate m3u playlist thru MAC address of this specific tv box, so I can use only channels that I pay for them.

Thanks! This is exactly for same provider I need information for.