Command line switch to source a script
From Vim Tips Wiki
created June 26, 2002 · complexity basic · author Max Ischenko · version 6.0
Use the -S option to start Vim and source a script file:
gvim -S foobar.vim
This tip is trivial, but I see the following too often. Time to update your mind!
gvim -c ":so foobar.vim"