Admin framework - advice needed

[garethdjames]

I am looking to build (or utilize) an administration framework,

We have many admin (back office) tasks that manipulate data that
affects live web sites,

Currently we have web forms, windows forms, scripts, etc.

I would like to rationalize these into a single high level way of
applying administration,

My first idea was to use a "snap-in" type approach.

For all admin tasks the following "concepts" need to be applied

Authentication and Authorization (roles and groups)
Auditing

All admin forms should be easily accessible, different functions on
each form may be restricted to certain users / roles / groups

I have had a quick look at using MMC but I can't seem to find out what
type of security model this offers.

Any advice would be greatly appreciated