Standard Browser for Files in Another Branch?

System

From a DCT I need to be able to browse to and select a file in another branch. I know there have been threads on this before and if I remember correctly the consensus was to develop something custom. I would like to avoid the copy/edit/maintain cycle if I can and keep the user experience consistent. I am also concerned that in another release (such as 6.0 even - I am on a 5.5.2 project) the CGI parameter passing API may change or otherwise require rework of CGIs.

I am wondering if with a FormAPI onCallout I can pass the appropriate parameters to the standard file browser to direct it to another branch.

Has anyone done this? Is it a good idea? Is it supported? What are the required parameters? It looks like they are all passed on the URL:

/iw/webdesk/WorkareaBrowser?allownewfiles=n&extns0=File+types+for+File+Name%2c.jpg%2c.gif&location=&topdir=&iw%5farea=/blah/blah/blah/WORKARA/john&show%5fthumbnail=true&callback=opener.formframe.browserCallback__43

Thanks,

-John