How to map PageDown to Option?
Try saving something like this as private.xml:

&lt;?xml version="1.0"?&gt;
&lt;root&gt;
&lt;item&gt;
&lt;name&gt;test&lt;/name&gt;
&lt;identifier&gt;private.test&lt;/identifier&gt;
&lt;autogen&gt;--KeyToKey-- KeyCode::PAGEDOWN, KeyCode::OPTION_L, VK_OPTION&lt;/autogen&gt;
&lt;/item&gt;
&lt;/root&gt;


I'm not sure, but it might not work if you don't have another keyboard with an option key connected.

If KeyCode::PAGEDOWN doesn't work, you can see the key code constants in the source and the hexadecimal key codes with Key Codes.

The test folder has an XML file with all the predefined remappings.