Yes, such items do exist. See for example:
However, some time ago I bought a Sitecom 11b card and adapter for a desktop. When I upgraded to a 11g wireless network, the new card would not fit the adapter so I had to continue with the old card.
You might have to do an extensive search on Google to find what you want, then agree a return if it doesn't fit (you will have to pay the return postage). By the time you have dome this, you might be better off buying a pci wireless card, e.g. click here or click here