In the application of one school, the directions for recommendations say, "...from full time or part time employers, colleagues, or clients..."

If I were to point out a weak point in my application, it would be work experience. When I apply, I will only have had 2 years experience. On top of that, I am working out of the country in a job that doesn't really require me to interact too often with my co-workers. I have already procured a letter from my supervisor, but his English isn't so great. I have an old professor that writes brilliantly and actually knows me better than any of my co-workers. She could attest to not only my academic ability, but my work ethic as well (I was working 40 hours per week during college). We also worked together one on one on a research project because I was chosen to present at the Student Research Seminar. I know that the rules say "employers, colleagues, or clients", but I think a letter from my old professor would put me in a better light than a letter from a co-worker that barely knows me and can hardly write in English.

I thought I would ask here first before I ask the school. Do schools bend on rules like this, or is it set in stone? The school in question isn't SO highly ranked (near-elite frontier I believe). What do you think?