Moving music files from PC

I'm somewhat new to this so I hope I'm making sense and someone can help. What I want to accomplish is sending WAV or FLAC files from my computer to my Alesis ML9600 HD. I download a lot of digital soundboards and instead of burning them to a CD then playing or uploading them on the Alesis, I'd like to play (or transfer if possible) the files on my computer to be recorded by the Alesis which will allow me to record them as 16, 20, or 24 bit and 44.1, 48. 88.2, or 96k (uploading from CD is 16/44.1).

My computer only has USB, SCSI, LAN, and Firewire connections. The Alesis has RCA and XLR digital inputs. Can anyone give me some idea if what I want to do is possible or how I can go about it. Alternatively, I can transfer the lossless files to my Rio Karma which has analog outputs. I suppose I can hook these into the Alesis analog inputs and play the music on the Rio while it records on the Alesis. The sound on the Rio is pretty good, but would I have to worry about jitter?

Thanks