Protect c:\inetpub for sub domains..Remote without Sandbox

Hi folks, I am on a cfmx 6.1 server on win2003. I work remote and do not have access to the full cf admin. Our hosting company denied us use of sandbox on sub-directories.  Here is the senerio.  We are resellers, but wanted to make sub domains and offer a cheap cheap cold fusion plans, but realized anyone could execute the cf code and if not done correctly could be a hazard if they are a newb.  So, since we cannot use sandbox on them, is their a way to write a Application.cfm that would protect our c:\inetpub\ourdomain from poorly written cf code. Example: simple file upload----say we put them on c:\inetpub\ourdomain\thierdomain....and they forget to add their domain and use c:\inetput\ourdomain by accident and then upload default.cfm......they might think it did not work..but all the sudden we have a new homepage right!  So, i am looking for a way to protect us from that and have no idea except for sandbox....but like i said..our remote company cant give us that interface without paying $529 a month lol! i was thinking something like an application file that would look for c:\inetpub\ourdomain.....and if that is all it saw....delete the file/ or better yet...dont allow it.  Please advise! As i realize i could do this from home very easily..but we are remote. Also...our remote host DOES allow us to create new application points for folders.
Thanks for all the great support out here in the world.
Jeff
http://Pro-web.us
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