reuse business methods as DLL in another project ???

Hi all,

I Have Core Project [3 tier Presentation-business-Data] include Core
functionality, I want to reuse the Core Business functions in another
project because the 2 projects using the same database.

Lets Say this is the Case:

CoreProject: Presentation->business->Data->DB

NewProject: Presentation->business->Data->DB

and


Presentation->CoreProject.business->CoreProject.Data->DB

My Question Is: How and where to add the Core business DLL in the new
project? And in case I want to add the Core business DLL reference to
the New Project Presentation there is conflict because of 2 businesses
DLL (the same name).

Thanks

Ashraf