Making an older laptop wireless capable

I have an older laptop with no powered PC slots or USB. It is essential to my business as it runs a CADD program built for Windows3 with a three button DOS mouse.

Given that fact which we have established over some years - hence the continued use of this machine - how can I connect it to a wireless network ? PC Cards need a powered bus - the card this machine takes are the original ones with no power. The machine does have an Ethernet card added so it is wired network capable.

Can I add an externally powered wireless device through the Ethernet port ?? If so has anyone any recommendations for hardware please

Peter