How do i make let's say a door unlock if someone does something(like pula handle. How do i make a handle?

[Voxel]

not sure what you mean. just a functioning door? or you want a triggered door? never done triggered doors but i'm guessing... make the door a scripted object, create a trigger. you hit the trigger and door opens. can trigger an explosions and blow the door up, etc...
look into trigger tutorials. simple door is much easier...
http://www.viziongrafx.com/moh/tuts/doors.html