Killing off the spaces of 1.5k songs would take some time
If you are talking about editing the space in a file or in a data storage in mIRC, by another characters, it can be done programmatically, it wouldn't take time at all.
I don't think you can 'connect' Excel and IRC, can you?
As in let IRC fill in and retrieve the info?
You can use COM object to communicate with an excel application, I'm not so sure about what you can do exactly and/or if you could do what you're looking for though, never looked into it, I don't have excel.