jStarDict allow you to set the navigate keys in the explaination area. You can do it in Settings->Explain Settings. You can set individual keys for each function like page up,page down,move left, move right,move up, move dwon, home/end, and select extend/compact. You can also use a setting file. Please put the setting file to dict\config\control. Then you will find it in the Setting list in Explain Settings.

Here is an example  setting file for BlackBerry 8100.