how to handle new page on cms html ? (being relatively safe?)

i am building cms that is base on html files.
how the user can add a new html page?
can i create that new file on server and still being relatively safe? 
on the html =
for dynamic content : [  i use ajax + web service + caching ] , for static content : [its stay as html txt - not from database]

so what options do i got?
how to handle new page? 
to grant w\r permission on some directory on the host and File.Create(txt, "index-2.html")? than to move it to destination directory?

thanks :)