In general there is no way to force windows to select a certain router. I have seen discussions in other forum that people talk about editing the registry to force it to connect to a particular mac address. The SSID maybe the same but they still have different mac addresses.
What windows does is it selects the strongest signal and connects to that. In general that is always the best option.
I can not find where I saw this. The issue they were talking about was there were identical SSID but someone was intentionally duplicating it to attempt to block/hack traffic.