You must be sure how your equip is connected to the computer. If you have a WLAN accesspoint and both your computer and mic/mouse are connected to it, a standard wireless lan repeater should extend the range. Be sure it is configured correctly! You can test this with an other device like a smartphone or laptop.
If your equipment is connected directly via WLAN to your computer (ad-hoc) there won't be a good chance to extend the range. you could buy a stronger wlan adapter for the computer, for example. The other option would be to connect them both to an infrastructure network (see above).
I'm wondering why one would require such a high range for this equipment.. If you maybe like to enjoy listening to music in the cellar and your router is incredibly far away, have a look at LAN/WLAN bridges. Have in mind a repeater is sometimes a dangerous thing, so laying a LAN cable to your favourite location and there setting up this bridge for a very local WLAN would be worth a thought.
Edit: @ your first sentence: There is nothing else in wireless LAN than "Wireless "Internet" signals". just don't call them internet but network signals. Well of course there is a lot of overhead for the communication.. But there are no different "WLAN-Types" for Internet connection or mouse connection!