Firstly, 'thanks a pile' sounds a little strange. It may be better to say 'thanks a lot' (though you have to be careful because this can sound sarcastic in the wrong context), or just simply, 'thanks'.
Secondly, unfortunately I haven't heard of an idiom with that exact meaning. But you may just say 'The best way to give someone advice is to advise them on how to achieve what's already in their heart', or something similar. Perhaps 'how to achieve their dreams'.