I need help with my game

Me and some of my friends are making a game like empire earth or starcraft/warcraft. The biggest problem that we are having is trying to get any object to move where the mouse clicks. Any basic code will help, just need an object to take the shortest route to the location of the click. Also how would you make a mini map? We need one that will show where the enemies are in relation to the real map. The objects would have to move proportionately to the objects on the large map. Any help would be greatly appreciated. Thanks in advanced.