Exporting .avi videos with a specific bitrate

am trying to stitch together muliple .mp4 videos to export one .avi video.

Up until now I have used the program Xilisoft to do this (so I know it can be done) but it is extremely slow and painful.

I have figured everything out using Adobe Media Encoder but cannot manage to export a video with a bitrate of 12000kbps. In fact, I cannot find any setting to manually change the bitrate for an .avi export.

Can Adobe please include a function where the bitrate on .avi outputs can be adjusted?