how to call dll static

Question

hi,
I am using a dll.i want to call the dll statically,means i have used like this
 [DllImport("Connector.dll")]
 public static extern void iaxc_set_preferred_source_udp_port(int udpPort);
Even though it is not working properly,when i run the application,it is checking whether the dll is existing in application folder.but i dont want to put the dll in application folder.Even i tried to hide it.But it is not possible?Is there any way to do call dll statically?