Know-How Exchange : Branding

I am currently doing a Corporate Branding exercise for a rapidly growing Business Process Outsourcing (BPO) company. The industry is extremely undifferentiated with similar service offerings across companies. Top management involvement with this exercise is marginal at best. However, I believe it is imperative, as the company moves into the big league, that a Corporate branding and positioning exercise is undertaken and the message is diffused to all relevant stakeholders, to move from a push to a pull model. How should I go about understanding and creating a Corporate Brand? And how should I get top management buy-in? Thank you.