The ability uses the word "attack" in the strict rules sense. See What counts as an attack? for a summary of that, but essentially provided you are not using abilities that require you to resolve an attack roll or that are called out as being attacks or damaging in the rulebook, all is good for maintaining the charm.
Unfortunately, what you cannot do is make the target do anything specific. The target is not compelled to do as you ask. As he/she "idolizes you" there is a strong chance they would voluntarily act on your behalf or do as you ask. However, they will still act as themselves in order to resolve issues. It will all boil down to how the DM interprets the NPCs personality.
In this case some obvious actions might be:
The lawyer declares to their client that they can no longer work for them.
The lawyer, whilst still following court protocol, deliberately performs badly at the task of suing your character.
The lawyer proposes to change sides and act on your behalf (perhaps they even know some nasty secret about their current client).
Some of these things may not resolve completely inside the hour. As a DM, I would generally be looking to make this gambit worthwhile (it has cost you a use of an ability, and presumably required planning to get the lawyer alone before the court case) whilst making it interesting at the same level as the plot point that started it. If it was all some aside that was distracting from the main adventure, I'd probably let it run as you wish and make a note for next time you were in town to continue the arc because it might be fun. If resolving the court case was the main story, I'd be looking for ways that it would give you some minor advantage (because it is a slick in character move) that moved the plot forward, maybe giving you a chance to achieve something else - e.g. go investigate the what was motivating the character suing you or improve your bargaining position if you would end up in debt.