“Leaders must role model what GREAT looks like.”

In her comments at  the “Fortune Most Powerful Women Evening With…” dinner in New York City Tuesday night  McKinsey & Co. ‘s Joanna Barsh was talking about the importance of corporate women leaders helping middle managers. But her comments helped set the tone for the evening, which also recognized a group of international rising stars who have been mentored by some of the most powerful female executives in U.S. business.

Barsh’s comments–she serves as a leader of McKinsey’s consumer packaged goods and organization practices–kicked off a star-studded evening that included such high powered guests as Xerox (XRX) CEO Ursula Burns, Frontier Communications (FTR) CEO Maggie Wilderotter and financial analyst Meredith Whitney, media stalwarts Barbara Walters, Sandra Lee, and Martha Stewart –and two daughters of former U.S. Presidents: Chelsea Clinton and Barbara Bush.

For all the star power–and corporate power in the room–McKinsey’s Barsh had a sobering message: Women still struggle to advance in business settings due a number of institutional and personal challenges. Her message: high-ranking women need to help women in middle management (they make up about 37% of mid-career ranks) to advance to the top tier (where women comprise about 27% of the population).

“Helping middle-management women to develop and advance will make the biggest difference because it will begin to reshape the corporate talent pipleline,” she said.

Many of the women at the dinner already are helping to reshape the corporate landscape by serving as mentors in the Fortune/U.S. State Department Global Women’s Mentoring Partnership. Mentors and their protégés –some 26 women from 16 countries around the world–talked about the value of mentorship and the tips and skills they gleaned from shadowing senior women such as Wal-Mart Stores’ (WMT) Susan Chambers and Solera Capital’s Molly Ashby and Goldman Sachs’ (GS) Dina Habib Powell.