I am connected to a wireless internet network (801.22b) in my
neighborhood. The network is for public use so everybody is allowed to
connect. In my home I am able to connect but only when my notebook is
right next to the window. I would like to place the notebook on my
desk which is in another room, about 30 feet away from the window.

Is there any way to do so? I am thinking of a repeater or a stronger
antenna. The repeater would have to be able to pick up a signal even
though I am not able to connect it specifically to the router of the
network. And the antenna might be difficult because my wireless card
is built into my notebook and has not plug for an antenna.

If you know any way which makes it possible to extend the wireless
network about 10 m to the other room please send an answer.

A couple of options here. First is a repeater, which acts as a second
access point, but uses the first's internet access. D-Link makes one
that can do both repeating and standard access-point procedures --
http://www.bestbuy.com/site/olspage.jsp?skuId=6759778&type=product&id=1088680027236

Your other option is a directional antenna. This would sit on your
desk and greatly improve the signal of a wireless card in your
computer. It would not, however, work with your built-in adapter, you
would need to get a PCMCIA wireless card with removeable antenna. The
D-Link product below would do the trick, but you'd need to buy a
compatable wireless card.
http://www.bestbuy.com/site/olspage.jsp?skuId=6682967&type=product&id=1083711426397

Finally, you could combine a directional antenna with an ethernet
bridge, which would allow you to connect easily to an entire home
network, because it would be through ethernet. This is not my
recommendation unless you want to supply internet to multiple
computers.
http://www.amazon.com/exec/obidos/tg/detail/-/B000066JQU/104-9627709-1898357?v=glance

Your best bet would be the repeater -- once you configure it, you
could use the internet from the community node anywhere in your home,
and others could use it to get a stronger connection.

Good luck.

Matthew Rasmussen