It looks like this can be done in Tour mode or Quickplay so whichever works for you. Here's the list of songs with solos (48 songs total):
Ohioman101 provided me with the number of solos for each song. I'm still going through and adding in where these solos appear and bolding ones I believe to be the difficult ones.
Ain't Messin 'Round [2 solos]
Albert [2 solos]
Arabella
At Night In Dreams [2 solos: middle, end]
Birth In Reverse
Caught Up In You [2 solos: late middle, end]
Cedarwood Road
Cold Clear Light [2 solos: late middle, end]
Dead Black (Heart of Ice) [6 solos: 2 beginning, after 1st verse, slow part, late middle, end]
Dream Genie [2 solos: one-third in, halfway]
Fever [end]
Follow You Down [2 solos: middle, end]
Free Falling [2 solos: late middle, end]
Friday I'm In Love [2 solos: middle, end]
Hail to the King [late middle]
Halls of Valhalla [3 solos] [beginning, middle, end]
I Am Electric [late middle]
I Bet My Life [end]
I Miss The Misery [end]
Kick It Out [end]
Knock Em Down [middle]
Lazaretto [2 solos] [middle, end]
Light the Fuse [middle]
Light Up The Night [early end]
Little Miss Can't Be Wrong [2 solos] [early middle, end]
Little White Church [late middle]
Mainstream Kid [middle]
Metropolis - Part 1 "The Miracle And The Sleeper" [3 solos]
Milwaukee [3 solos] [beginning, middle, end]
Miracle Man [middle]
My God Is The Sun [2 solos] [early end, end]
No One Like You [3 solos] [beginning, early end, end]
The One I Love [late middle]
Panama [middle]
A Passage To Bangkok [late middle]
Pistol Whipped [middle]
Rock and Roll, Hoochie Koo [middle]
The Seeker [middle]
Spiders [middle]
Start A Band [4 solos] [beginning, early middle, late middle, end]
Superunknown [2 solos] [middle, end]
That Smell [5 solos] [beginning, late beginning, middle, late middle, end]
Toys in the Attic [2 solos] [middle, late middle]
V-Bomb [early end]
The Warrior [late middle]
What's Up? [3 solos] [beginning, middle, end]
You Make Loving Fun [2 solos] [middle, end]
Your Love [2 solos] [late beginning, end]