Can I use my android's wifi to let another device to connect it through wifi?
No; your phone can only connect to one wifi at a time. (Unless you add a usb-otg AP and write some code to make it work.) Although there are multi band wifi chips in phones it's unlikely the driver has the liberty to make the hardware work that way and writing your own driver is not practical anyway.

A more simple solution is to use curl on your (non-android) computer in the place of a web browser but the details of that are better left to stackoverflow.