The C and R settings can be set in the Configuration tab. Once you have connected to the local XBee with magnifying Glass Icon on the left, click on the Gear Icon on the right. This will read the Xbee configuration. Scroll down to the Network section, and look at the CE entry.
The range test is under the Tools item, Spanner and screwdriver. This will try to discover remote node and then run the test on the selected node