If such a list exists online, I've not found it, and I have looked extremely hard.
The only centralised lists of all new releases I've ever found used to be be in Music Week. That was only BPI-affiliated artists and labels, but as that includes pretty much everyone, it's about as comprehensive a source as you'd find.
So, it's either back issues or give us a hint. They're pretty good at this site you know, even if you've only got a vague idea of the song. And a challenge is always welcome.