computer geek help,banned-hide mac addressvia.network ethernet pcmcia??

i have a dell inspirion xp laptop and i got banned from a gaming site,(my cuzin got banned and i cant open another account via through my laptop...o know its not my i.p because i went to starbucks and when i downloaded the game (cards) cleint it recognized me when trying to set up another account ..it stoped me and told me my account was frozen. i also tried this at my house , so my i.p is another thing, Here is what a geek from best buy computer center told me to do... buy a network wireless pcmcia and it should mask my mac address when i pay, is all this right???