Will probably add this to my journal modification soon, but
To go about it in the UI, you would make a button first and add the command to the OnPress property...
such as:
Code:
<Button Name="EQ2i" OnPress="URL='http://eq2.wikia.com/wiki/Special:Search?search=' ## Parent.Parent.LorePage.Name.Text
browser URL" ScrollExtent="15,15" Size="15,15" Style="/ButtonStyles.tabscroll_left" Tooltip="Search EQ2i" />
This is similar to the code I use in my Examine windows.
The "Parent.Parent.LorePage.Name.Text" part needs to be changed to point to the Text object in the journal that display the quest name.