Some view it this way: 1 Jesus was the original authorizer of Jesus Name baptism, who authorized the Apostles, Mt 28.19. 2 The Apostles authorized others to also baptize, by laying on the hands of the presbytry.
1 Timothy 4.14. This view makes preachers the only authorized persons and those who haven't been 'sent forth' by those who are authorized as unauthorized.
Some trivia: 1 Some will say that only a person who has been baptized in Jesus name has authority to baptize another in the Name. But which authorized person performed the first baptism? 2 Jesus never baptized anyone in his own name. 3 Somewhere along the line, the Apostles must have realized that they weren't baptized in Jesus name and then must have started to baptize one another, though some had been baptized by a validated baptizer, John Baptist.
If you choose to baptize your friend, before doing so consult with the Pastor of your church. When baptized, you are entering the Body of Believers and a local church, but if the new convert is entering-in to a fellowship on a point of controvery, then its not the best way to start out.
If an authorized baptism is the only valid baptism, what does this say of the power of the Word, or the power of the Name? Doesn't saying so add a step in the validation process of baptism which isn't clearly commanded in Scripture? Would adding a step to the validation process be undermining the power of the Name?