It's a laptop so no, the "card" can't be upgraded as it's
integrated sound. However, you might have a miniPCI slot
with something in it you could remove, or empty that might
accept a miniPCI sound card, but come to think of it I've
never actually seen one and it's more likely you do have
something in a miniPCI slot if you have one (like a Wifi
network card).
As for other interfaces of sound devices, a USB dongled
audio solution might be the best alternative.
http://www.google.com/search?q=USB+audio
(or visit your favorite online or B&M store to see what they
offer).