Cisco Firewall :: ASA 5510 / URL Paths And Regular Expressions In ASDM?

I've recently switched to an ASA 5510 on 8.4(3) coming from a Checkpoint NGX platform (let's say fairly quickly and without much warning ). I have a couple questions and they're kind of similar so I'll post them up. I've read docs about regex and creating them both via command line and ASDM, but the examples always seem to include info I don't need or honestly something I don't understand yet (mainly related to defining classinspect maps). If someone could provide a simple example of how to do these in ASDM that would be useful in understanding how regular expressions are properly configured. So here we go.

I know this is basic but I need to make sure I understand this properly - I have a single web server (so this won't be a global policy) where I need to allow access to a specific URL pathfile and that's it. So we'll call it est estfile.doc. Any other access to any other path should be dropped. What's the best way to do this in ASDM (6.4)? I think if I saw a basic example for this I could figure out next few questions but I'll post them as well just in case.

I have another single public web server (again this won't be a global policy) where I'd like to specify blocking file types, like .php, .exe., etc... again a basic example would be great.

Lastly, and this is kind of related, but we have a single office/domain and sometimes we get spam from forged addresses appearing to be from our domain. On Checkpoint I used to use its built-in SMTP security server and could define if it received mail from *@mydomain.com to drop it because we would never receive mail externally from our own domain name. I saw something similar with ESMTP in ASDM and it looks kind of like how you set up the URL access mentioned above. Can I configure this in ASDM as well, and if so how?