Cover Letter, Sales How Can I Write A Cover Letter For (sale Executive Person) Position As Long As Am In A Different Field?

How can i write a cover letter for (sale executive person) position as long as am in a different field? - cover letter, sales

I'm still in the field of academic information next qualifying period I developed a good professional experience as an executive secretary, over the years and now I am interested in the application "sales where the person the executive," I wonder what I am in my cover letter!
Note: The company I am applying to ask, not a single title of skills and good looks!