First off, with your background in branch banking and your interest in numbers I would recommend that you consider a lateral move to the Finance department of the bank's headquarters, a logical transition assuming you still like the banking environment. Another avenue to consider would be possibly returning to school for your MBA in Finance. Headquarter's fianance groups love to staff themselves with MBAs.
I transitioned from clinical psychology degree in Southern California to an MBA working for Citicorp in Manhattan, go figure. As they say in Germany, alles moglich.
Good luck to you I hope things go your way. I am leaving the office for a meeting all day, if you have further questions feel free to pm me.
Greg