I have a collie x who is exeptional at home, etc. But when down shows he plays up, and even ignores hisfavourite treat. He looks at the other 2 dogs we own and get distracted by them. I dont know how to gain that pack leader relationship.
Can anybody help?

I don't think its a pack thing - I think he just finds everything else more interesting than you - thats what you need to work on :)