Are you applying for any of the vacancies? Do they have different criteria? You have the right idea - it's all in how you visualize the situation. Are you interested in any of the various vacancies, or - if they are all identically defined - then you are really only interested in a position within the company.
When you really think about it, you are not really even interested in a vacancy (or the vacancies). You are interested in a placement. Not a vacancy. I would suggest you re-cast the entire sentence to stress that:
I am interested in a position with ABC.
Student or Learner