This is a bit tuff to physically able to see the rdl's. But, its acheivable!!.
In my last project, i created a c# console app and added the reportingservice webservice to my app. (we had to create a back of RDL's in a network drive so every one who is not a user has access to it).
You can pretty much see/process everything including the folder structure of the reports being stored in.
There are only three types, i believe 1 is for a report 2 is for datasoruce and 3 for a folder. Dont get confused these are the values assigned to them in a table under ReportServerDB.
If it's report then read thru StreamReader and read it to a file and save it as .RDL as its pure XML. If you want the folder structure also, use system.directory class. to create folders in your computer.
Hope this give's a direction atleast.
Here is the link for RS webservice.
Try adding it to a console app and browse all the methods thru object browser. you should get a feel. You can even save/disable/enable data driven subscriptions through the web service.
It's a power ful tool, dont try it on production DB. If no progress, let me know. I can help.