Map with all the node but focused on a specific one (passing argument through URL)

Hi!

I'm trying to display a map with all my nodes of a specific type (up to this, i managed) but focused/zoomed on a specific node by passing arguments (node id, long, lat, zoom ?) through the URL.

For example :
http://mysite.com/map > display an unzoomed map with all the nodes
http://mysite.com/map/nid > display all the nodes but zoomed on 1 node (nid)

I tried to use a view but i only managed to display a map with only 1 node. (by creating a Contextual filter on Nid provided by Raw value from URL).

Could anyone help me?
Thanks in advance!