Absolutely. When I look for people to promote into project management, I'm going to look at those that have demonstrated a strong interest through self-improvement. The new PMP rules do require you to lead and direct project tasks, so I would work with an aspiring manager to provide opportunities to do just that.
If your employer or manager is not willing to do this, it might be a sign that your credential is either best earned elsewhere or when you earn it, you may look for a different position in another company.
Keep in mind that being promoted to a new position requires both ability and opportunity (e.g. the company has grown and has justirfication for a new position).