No, there is no any special low which can provide you with visa if you are not married with your fiance, even you have common children. You can come to Russia to marry and make permission for temporary residence without quotas for three years.

Dobry den! Izvinite, chto pishu latinskimi bukvami, no u menja net drugoy klaviatury. Ja zhivu v Estonii, u menja seychas gosti iz Germany. V Rossiyskom Konsulstve v Mьhhene oni sdelali vizu v Russia bez vsjakih priglasheniy. V hodataystve o vize oni ukazyvali tolko(est kopia), chto hotjat ehat v…

belarus-in-russia.by.ru/?C=S;O=A

You need to go to Russia and marry russian women, its the start of your russian nationality/.