Commerce Portal link with existing website

Hi All

I have a query…

Can we link an existing website to the Navision using Comerce Portal or any other tool.

Online sales is done thru the website and this need to be updated in the Navision database. I know we can do this using Commerce Portal put we will have to design the site with the portal. But what if the customer wants to run the existing website . can anybody suggest me some solution.

Thanx in advance