Unless you are working with a well respected publisher, or have representation (such as an entertainment attorney or manager) who has connections, the chance of getting a song into the hands of a specific artist are slim to none.
To rain on your parade just a little more, the likelyhood of getting in with a publisher (at least a well respected one) or your chance of getting high profile representation is also slim to none, unless you have an established body of work (meaning several songs published, placed, recorded and generating revenue).
If you beleive in your song and you feel it is well written, well recorded, has an excellant vocalist on the demo, etc - by all means try to get it published - but don't expect it to automatically get picked up by a name artist.