It's great to have a career related goal, whether that be a big or small one. It could be a promotion or an additional designation that you'd like to achieve. Talk a little bit about those particular goals with the hiring manager but be sure to tie it in to how this will also benefit the company you are interviewing with.
"As a Sales Engineer I would eventually like to earn my way into a Management role where I can mentor and train other Sales Engineers. Being able to attend school again and complete an additional designation within engineering or technology is also something that would be of interest to me."