Amunk...Try the Oriico Gold Card with External antenna input for your laptop:
Excerpt from CNET review...
The Orinoco World PC Card also features a unique external antenna connector .... Simply attach an indoor antenna such as the $70 Proxim Orinoco Range Extender model to the end of your PC Card via the included cable. You can then place the external antenna up high on a desk or a bookshelf and increase your wireless coverage.