Nmap command line syntax ?

["Richard Pawly" <rpawly () gmail com>]

Can someone pleas help me with a syntax to start Nmap to do the following:

Import ip address list from file (btw what format and contents should
the file contain)(can i use DNS name??)
export results to a file ( i only need to see open ports if thats a option)
to still scan if does not respond to ping
i only need to scan tcp/udp ports on routers
can i scan 10,000 hosts in one command line, or 1 file import of hosts??

I appreciate any and all direction.

Thx

Rich