If you mean your laptop receives the wireless, then it sends it out through an ethernet cord into your 360, then I have a solution.
Step 1:
Left-click this
Attachment 22876 Step 2:
Right-Click the Wireless connection that you are connecting to. Then select Status.
Step 3:
Select Properties.
Attachment 22877 Step 4:
Select the Sharing tab and then check off both boxes.
Attachment 22878 Step 5:
Click OK, then turn your Xbox 360 on and attempt to connect to XBL.
It works for me but not for some apperently.