Advice for cover letter?

I want to apply for this job - Senior Mortgage Officer (disbursement). I have 9 years experience doing this type of work am well-qualified for the job. The only thing is that I have not worked in this area for the last 10 years because of various reasons. How do I write a convincing letter to the employer to let them know that I am passionate about this type of work and that I will be able to cope with the work even though regulations have changed over the years and the fast paced working environment? I have tried to apply to this finance company before, but did not get an interview. I really want to get back to the finance industry and I really enjoyed this type of work in the past as it gave me great satisfaction and a sense of achievement. Please give me some advice. Kindly don't refer me to websites for cover letters. I have already looked at those- not much help.