Yes, you can do that by calling the desired topic as as a reference to the help' s _csh file. Or less complicated: look in the output folder of your webhelp and you will see the file for the default topic and also a file with the same name, but "_csh" attached. When you call that file you can pass along the map ID, alias, or file name of the topic you want to have displayed. This _csh file is used as entry point and loads the framework as well as the topic that you specified. The Flare help has a topic that outlines this nicely.
You can find that topic also here in the online version of the Flare help:
http://www.madcapsoftware.com/support/w ... lopers.htmI find the URL method to be the easiest, but it all depends on personal preference and the application itself. One method may work out better than the other or vice versa.