Hi,
You could try using 3-rd party packages using opkg, I believe you should find HTTP server hosting packages there, but you should look for it yourself.
Then if you use it, you would need to have some kind of session or login tokens integrated into that same HTTP server that you would run on the router and then you would need another server in that internal address to accept the token if the login was correct.
In any case, this requires some research, but it's possible.
EB.