You can use a tool to edit your save (you create a game, save and quit) to modify everything, even you actual progress, and select the mission you want.
You can try with Gibbed Mass Effect 3 Save Editor, which is the most popular an easy-to-use editor. Here how to use it: http://benchmark3d.com/mass-effect-3-save-game-editor
Here you have the mission code (from this source):
59915 Priority: Palaven
You can use this code under the Plot Mass Effect 3 tab, and Missions sub tab.
