I assume you know now that you're not supposed to remove that philips screw unless you're ddismantling the lower unit.
As long as you haven't been shifting the unit back and forth, you might still be able to see a portion of the hole in the inner shift lever. If so..... file the end of the pivot pin so that it has a sloped chisel edge. That shape may allow you to maneuver the pin back in there. Also a pointed scribe such as a ice pick may allow you to gently raise the lever where it belongs or close to it.
Other than that... Turn the engine upside down and hope that the lever falls into place, OR remove the lower unit so that it alone can be turned upside down.