Day for night interior against large window with available light

[Scottie Mei]

Hi, I am shooting a short with F900/3, and I needed help to figure out my lighting. the scene takes place in a warehouse type of apartment loft building with few 7'x5' windows in background. the director wants moon light to be the only light source for the scene, and still be able to see the city's "NIGHTSCAPE" through the window.that's not all, it is going to be a day for night scene with available light. I tried pitching the idea of ND the windows and use scissor lift,condor or balloon light to to light those windows from outside as it is a 3 story building, but the is no budget for those equipment. Also, I will only be able to gel those windows from inside. my idea is to ND down the window and gel them with 1/2 CTB and have the production designer dress those windows with roll down curtains and have those curtains half way down. that way, I won't have to deal with the sky, but I will loose the ambient light in the apartment. I am not sure if my idea is going to work. please let me know if anybody out there has any ideas. I am shooting in a week and I am dried out of ideas. I have attached a picture I took at the location to give you some idea of how it looks like.thanks very much