I take it that MIP stands for Minor In Possession. This is a misdemeanor in the states where I practice and, at the same time, I am not a misdemeanor or juvenile attorney, however, "getting a charged dismissed" has to do with the appraisal of the case and the charge by a prosecutor and the work of a defense attorney. Criminal cases are about arguing the facts as they apply to the law. For instance, the fact that you never had actual possession of the alcohol is favorable to you, however, most, if not all, jurisdictions consider "constructive" possession as the legal equivalent to actual possession. Constructive possession means that while you may not have been holding the alcohol, you had, at least, partial dominion or control over it-- that it was yours to consume as much as it was your friends. There is some evidence-- stated by you-- that you gave the man money to buy the alcohol. Thus, there is an argument that-- since only one person could actually possess the alcohol at one time (assuming there was only one "bottle" or "container")-- you were at least part "owner" of the alcohol and could demand and receive it from your friend any time you wished. An opposing argument, for example, would be that the man who said you gave him money to buy the alcohol is not credible, that he shouldn't be believed for some reason, that his testimony is not trustworthy because of criminal background, intoxication, etc. This is just the starting point, but I think you can see that even the simplest seeming facts are complicated when analyzed properly. This is a defense attorney's job.
The first question that has to be answered is, what are the elements of the MIP offense in your jurisdiction? Secondly, do the facts known to the prosecution, fit the elements of the offense? A "dismissal" that is generated solely by the prosecution is the result of a prosecutor not having a good faith belief in the his (the state's) ability to prove offense. A defense attorney-- more adept at seeing defenses than a misdemeanor prosecutor-- would use negotiation skills based on his/her ability to see defects in the state's case in order to argue for a dismissal. Sometimes dismissals are an outgrowth of the prosecution's appraisal of your case but often are the result of the work of a defense attorney in convincing the prosecution that they do not have a likelihood of conviction if the case were to go to trial.
In short, if dismissal of the charge of MIP is important to you (or a reduction in the penalty you would be forced to pay if there is a likelihood that you would be convicted if the case went to trial) a criminal defense attorney is very important. Most people with experience and knowledge in the criminal law do not rely on the judgment of a prosecutor as to whether a case will or won't be dismissed. This is an adversarial system; it works best when a prosecutor AND a defense attorney work to resolve a case either before trial. Finally, if your case isn't dismissed and you end up in trial, a defense attorney is crucial to your chances of acquittal.
It is difficult to tell from your scenario, but the government may be unable to prove beyond a reasonable doubt that you possessed or were in a conspiracy to possess alcohol. You may also be able to enroll in diversion or your attorney may be able to work out an arrangement to dismiss the charges under these facts.
You should not discuss the facts of this case with anyone other than your attorney, and you should consult with an attorney as soon as possible to see if they can resolve it for you.