It might be worthwhile investigating why your laptop keyboard doesn't work. Are the contacts worn out or is it just gunked up?
You need to find out whether your laptop has a PS2 socket for a keyboard or just USB sockets. PS2 sockets are round and purple. USB are horizontal slots. Your manual should help. If you've lost it you should be able to find a copy from the maufacturer's website.
Once you know out what kind of socket you've got you should then be able to plug in a matching desktop keyboard. Note that some keyboards provide adapters to allow you to plug a USB keyboard into a PS2 slot.
Hope that helps.