wp-admin pointing to wrong address

Hi

I recently moved my wordpress site to a new domain everything is working fine except when I type …/wp-admin it redirects to the old address and therefore gives me a 403 error of access forbidden as that address is no longer there. My hosting company has advised that I change any reference to http://79.170.40.45/maggemm.org in the configuration script but I cant find any reference to that address anywhere in the site structure. My hosting company then suggested I check the MySQL files (as it may be there) but I dont know where to look in that structure.

Would I find it in the My SQL database files?…If so where?
If not where can I find it?

Thanks
Jon