Scales in and of themselves are not music... well, you could argue with that if you wanted to get technical, but it's not music music. I would keep learning scale patterns and learn where notes are on the fingerboard. Then, look up "intervallic excercises". These excercises will help you work scales into your memory and keep you from playing just up and down the scales. I've been playing with them for a couple months and it's dramatically improved how I play and write melodies.

You might post a recording of the song as-is, maybe me or someone else can point you in the right direction as to what you should play (in general, I mean.) Failing that, post what chords you are using and anything else that might be relevant (actually, I'd do that anyway), the style, and what mood you're going for with the lead.

I would also suggest getting a guitar teacher. Reading material online and being involved in guitar-oriented forums is also great, but it can't tell you if your technique is slowly tearing apart your shoulder or if you're on the highway to carpal tunnel. I avoided getting one for years, but I have been taking lessons for the last two and a half months and it's the best thing I have ever done.

---Bryan