Here are a few options. Save the pastebin text as a batch file (*.bat) in your ffmpeg folder. You can paste a shortcut to the bat file anywhere else you may want to have it, and it should work fine.
I can’t vouch for the aac conversion quality of FFMPEG, so you may want to convert to Wav, then use eac3to to convert to aac.
For converting 8 mono channels within a container file to a 5.1 AAC and a 2.0 AAC:
For converting 8 mono channels within a container file to a new container with original video, a 5.1 AAC, and a 2.0 AAC:
For converting 8 mono channels within a container file to a 5.1 16 Bit WAV and a Stereo 16 Bit WAV:
For converting 8 mono channels within a container file to a 5.1 24 Bit WAV and a Stereo 24 Bit WAV: