MOSCOW is opening a consulate in Hong Kong next month as part of an aggressive drive to attract investment, trade and tourism. Russian Ambassador to China Igor Rogachev said in Hong Kong yesterday that five or six diplomats would be stationed here. It is understood that the Consul-General, who will be named soon, is fluent in Chinese and English and has served in China and the West. ''Hong Kong is such a major international financial centre, we missed a lot by not having diplomatic representation,'' Mr Rogachev said. Mr Rogachev, who is Russia's premier sinologist, called on Hong Kong businessmen to take advantage of the opportunities afforded by economic reform. ''Our parliament is enacting new laws on investment, trade, and other aspects of the economy,'' he said. ''In addition to doing business in the big cities, Hong Kong companies may play a particularly large role in the development of Siberia and the [Russian] Far East.'' He disclosed that a delegation of central bankers had recently visited Hong Kong in search of investment. Last year, Hong Kong exported $2.44 billion worth of goods to Russia, most of them re-exports. Imports were a relatively paltry $706.93 million. Poland is the first country in the former East Bloc that has diplomatic representation in the territory. The Director of Protocol of the Hong Kong Government Vivian Warrington yesterday welcomed the setting up of the Russian mission. He said approval in principle had been given to Hungary and the Czech Republic to open consulates here. Both countries, however, have yet to begin the formalities of establishing their missions.