Dreamweaver is an editor/designer for web pages and you can use DMX to help build a Mambo template, but isn't meant to handle content in an open source CMS (dynamic) environment - so the short answer is no, Mambo isn't "connectable" in that way. (Yes, I know that DMX is capable of more, but...).
Mambo, like most CMS solutions I'm aware of, are frameworks that you apply your "style" to, and create and manage your content within the framework.
Think of a CMS like a house under construction, with the 2x4 stud walls up but no rooms are sectioned off... no paint, no landscaping. After the frame is up, you go in and make it your own by doing your own plumbing, electrical, etc. (components, modules, mambots) - then put up your own walls, and decorate it to suit your own taste with a template.
There are solutions that do what you're looking for, but they're costly and proprietary... GoLive, ColdFusion, etc.
However....! You CAN create a template just like your present site's design, and re-use your content within Mambo. It may be more copy/paste, than point and plug in - but you will ultimately have a near duplicate of what you have, that can be managed and edited in a CMS context. No more page by page editing.
