[Solved] How do I edit specific notes within a certain range?

You can open up the piano roll for that part, zoom out horizontally until the 10 measures all fit in the window, zoom in as far as you can vertically so the specific pitch you're targeting is as big as possible, then use right-click to select all the instances of that note in that span of time.  Once they're all selected, hover over the top of one of the notes until you get that bar-graph looking icon, which allows you to click/ drag up or down to raise or lower the velocity of all the selected notes.

The solution will depend on what you want as a result.
 
Do you want all the new velocities to be identical or do you want them scaled relative to the original velocities.
 
The first scenario is easy, select your notes (as described above) and just enter the new velocity in the Event Inspector.
 
For the second scenario, there are at least 3 ways to accomplish this, but probably the easiest way is to simply select the notes as before, then in Track View Right Click the clip and use Process Effect > Midi Effects > Cakewalk Fx > Velocity.
This will open up the plugin where you have total control over your new velocities