DotNetNuke and other CMS Question

[needin4mation]

I know this is an ASP.NET group. I have been to asp.net. I am hoping
someone will be able to give me the big picture here as no one as
asp.net has.

I have considered using DNN or some other portal product. I like DNN
and it is free and has a lot of users.

But what I am concerned about are "normal" asp.net pages and legacy
asp, etc. If I have a web page that hits a database and retrieves a
report, for example, I don't want to have to build a module everytime
to do that. And I am not sure if I am supposed to have a link in the
portal to a web page outside of the portal and link back into the
portal for other pages. I'm not sure if that is the "correct" way to
do things or not.

Using a portal product for ASP.NET. Does that mean I should build
everything in that portal? What good does it do me to get DNN if I am
not building a bunch of new modules (and what of legacy pages)?

I hope someone can kind of understand what I saying and asking and give
some advice.

Respectfully, I have been to the asp.net forums to no avail and I asked
it much simpler than this.

Thank for any help.