Map of all sub-pages of a page

I'm wondering if the solution you offered for "Category map of all entries/posts" will work for subpages as well.

I have tried to use this function in order to show the location of climbing boulders on my site. Each boulder has a page and all these pages are listed under a climbing parent page. Unfortunately, when I employ the function, it returns a map of all locations on my site, indicating that somehow I need to tell the function it has a narrower selection of content to choose from.

Any ideas on how I could do this? Maybe it is more of a question of template tags and php programming in WP. I hope not because I have no working knowledge of either.

PS - I've done a little looking around. Would something like this help? In a template based on the standard page template, I code before the loop a php script that basically says: if subpage of page# then ... and then in the loop include the map script. Sound logical?