Can you please tell me what dose the law say about woman saying the blessing of Hamotzi at a shabbat meal where there are men at. Also, can you please tell me where I can find it, so I can see it inside.

Women are obliged in Lechem Mishneh just like men. (Mishnah Brurah 274; 1) therefore can say the Brachah on behalf of men, though, it is better for a woman not to do so for men whom are not of her family for Tzniut reasons. (ibid 271 4; Shmirat Shabbat Kehilchata 2 p.143)