Before starting a job search, arrange a meeting with your superiors to discuss how you might leverage your skills in a negotiation job. Discuss your accomplishments and qualifications. Don't be disappointed if an answer doesn't come immediately. Employers need time to evaluate requests. Also, understand that your employer may consider two years too short a time for you to switch positions.
While waiting for a response, start your job search on the sly by gathering information about the job market. Talk with everyone you know about your career goals and ask if they know about opportunities for you. Also, use the Internet to identify jobs that describe the tasks you'd like to perform. Focus on job descriptions, not titles. Then if you find some you're interested in, use that information to tell prospective employers what you'd like to do.