Cisco :: BGP Selecting Paths - All Sites Are Configured With The Same AS Number (55555)?

I look after 5 sites in total.All sites are connected together via MPLS. Two of the sites, HQ1 and HQ2 are also connected together via 1Gb Metro so traffic is just switched between the 2 networks.EIGRP is fed into BGP to pass the routes between the sites with all sites in the same EIGRP AS.

All sites are configured with the same AS number (55555) and connect into the same service provider network so each site is connecting to a neighbor in the same AS (444).

I want all incoming traffic from the 3 sites to come in through HQ1 always. Can I influence the service provider's network to make sure this happens? Is this done via "set local-preference 20" on my side or do I have to get the service provider to make changes on their side too.