BEIRUT (Reuters) - The Syrian National Coalition, a group fighting the Syrian government, said on Wednesday it opposed a Russian-sponsored congress of Syrian groups, calling it an attempt to circumvent U.N.-backed Geneva peace talks that aim for a political transition for the war-torn country.   The Coalition will not participate in any negotiations with the regime outside Geneva or without U.N. sponsorship,  SNC spokesman Ahmad Ramadan told Reuters.  Russia s call for a conference for Syrians in Sochi is an attempt to circumvent Geneva and the international desire for a political transition in Syria in accordance with U.N. security council resolutions,  the Turkey-based SNC said.  