Easily done.

Start cutscene, then start conversation.

Player has no control beyond conversation options.

Conversation ActionTaken scripts determine what happens next.

Eventually a option must end the cutscene, of course.

Nuances:

Turn dialogue zoom off (or it will mess with the cutscene camera).

The module OnCutsceneAbort must either prevent escape (boring) or return the game to the desired final state for every option the player can choose (complicated) including a default outcome.

If characters need to move around during conversation, ActionPauseConversation prevents the PC from responding prematurely. The actor whose action queue takes most time issues ActionResumeConversation as their final action.

It's often convenient to have the conversation with an invisible object which is deleted after terminating the cutscene, to exit conversation cleanly. The lines can be spoken by actors by specifying their tags.

Remember that speakers need to be in conversation range. Moving the player might require a new conversation. Actors who are far away can have their lines spoken by invisible objects with the same name / portrait but different tags.

The totally unhelpful answer is: yes.

Basically, you're going to put the PC in cutscene mode, apply the cutscene invisibility and cutscene ghost effects and use them as your camera for the scene. For the duration of the scene you'll create a copy of the PC and put it at the location of the PC which will perform the actions of the PC.

You can take a look at the manticore cutscene in SoU and the introductory cutscene with the Valsharess in HotU to get an idea of how Bioware did it. That said, I found the way they did it unecessarily messy.

If you have NWN2, you might want to take a look at how OEI set up cutscenes in their campaigns. You have a few more steps in NWN, but OEI's cutscenes are a lot easier to follow than Biowares.

I do it a few times in my Sea of Shadow module

P.S. I always use the Gestalt Cutscene script package from the Vault - slight learning curve, but saves time, because everything works out-of-the-box. It handles issues like PC invisibility (if that's what you want) so you don't have to.