MORE than two hours in the driving rain and deep mud, waiting under a leaky umbrella to see Hillary Rodham Clinton speak, was trying the patience of Lucille Chalmers. ''I'm not really a big fan of the Clintons,'' the British activist said as she waited in the downpour outside the converted theater to see the American first lady. ''But Hillary took a stand and that meant something.'' After a week of good humor in the face of Chinese police scrutiny and poor meeting conditions, the frustration of thousands of private women activists spilled over into anger yesterday as they flocked to give a heroine's welcome to Mrs. Clinton. Ahead of her address at the Non-Governmental Organizations Forum in Huairou, Clinton had already won the hearts and minds of the women activists. Her speech at the Fourth UN Conference on Women in Beijing the day before was a clarion call for human rights. It also chastised China's heavy-handed police interference in the NGO Forum's proceedings. But when Chinese authorities restricted entry to the small theater and hundreds were turned away, the crowd furiously rushed the doors, guarded by a human wall of policemen. Clinton had been expected to address more than 10,000 participants in a makeshift outdoor theater, but torrential rain forced the proceedings inside. Outside, Chinese police blamed the chaos on an American decision to shift the event indoors. Betty Friedan, mother of the US women's movement, was refused entry. Even senior US officials got a taste of rigid Chinese security when Health and Human Services Secretary Donna Shalala and Winston Lord, the top American diplomat for the Far East, were turned away before they were allowed to enter through a side door. For the lucky 3,000 who pushed their way in and occupied every inch of space in the theater, the atmosphere was charged like a pep rally, feminist-style. And when Clinton finally appeared, their enthusiasm rose to fever pitch. ''I know you have had to endure severe frustrations to be here,'' she told them, referring to visa and security problems that have hampered the forum. ''For many ... getting here was far from easy.... You did not give up, you didn't stay away.'' Clinton assured the activists that their presence would make a difference on the women's agenda now under debate at the official meetings in Beijing but urged them to turn the words into action. ''You will be the key players in determining whether or not this conference goes beyond rhetoric and actually does something to improve the lives of women,'' Clinton said. LATER, in the makeshift tent city awash in mud and rain, women resumed their meetings and workshops with the good cheer that has pervaded the event. The NGO forum has often been a rollicking political free-for-all, a cacophony of causes with lesbians parading past veiled Muslim women protesting homosexuality, and abortion pro-choicers trying to outshout pro-life advocates. Women activists marched, demanding an end to US imperialism, the only demonstrations mentioned by the official New China News Agency. And Japanese activists demonstrated against nuclear testing. Even McDonald's, where activists have flocked for a bite, was the target of protests. Toppling the plastic Ronald McDonald from his bench out front, a group of American and Australian environmentalists exhorted diners to leave. ''Buying food here is a political act,'' shouted one activist as another stomped on trash and discarded french fries pulled from the garbage. ''I just want to have something to eat,'' pleaded an American woman who waited in line. On the sidelines have been Chinese women participating in such a forum for the first time. Chinese observers say interaction between their countrywomen and the international activists has been limited, reflecting official disapproval of the forum. Still, Chinese women have been among the most curious onlookers at protests. ''Can you tell me what is going on?'' asked one puzzled Chinese participant waiting in line at McDonalds. ''Why is that woman jumping on the potato pieces?''