Extend WiFi signal via WL-500gx

[iguana007]

Hello everyone,
I would like ask you for a little help. I am using Huaweii ADSL2 modem with wifi included. My WiFi network is secured via WPA2-PSK and it works fine at home. But when I try access my network on the garden (about 100 meters from router), signal is so weak, that I cannot connect.
I thought, that I could use my WL-500gx router as an "extender" of the signal. Is anything like this possible? If yes, what should I set up in the router?

Thank You for any help.

Luke