x11 xmodmap

hi everyone
i use a x11 programm (texmacs)
i want to reconfigure the mapping
- i have tried to save my xmodmap file in the home directory with names such as ".Xmodmap" or others, but in no case, x11 seemed to take this file in consideration automatically at the lauching; so i type in the commande line "xmodmap(space)" and i glide the icon of the file and it works but it is not comfortable
- my aim is: to affect the "C-" operator to the apple key, to affect the "mod1" operator to the control key, to let the alt key and the shift key make their work.
- with xev i have recognized the numbers of the keys
! 63 71 pomme
! 66 alt
! 67 ctrl
now i dont know what i have to type:
-- first possibility --
clear Mod1
keycode 63 = Meta_L
add Mod1 = Meta_L
-- second possibility --
clear Mod1
keycode 63 = Alt_L
add Mod1 = Alt_L
-- third possibility --
clear Mod1
keycode 63 = Mode_switch
add Mod1 = Mode_switch

is'nt there a quicker means to do this ?
can i not type for example
add Mod1 = keycode 67
add Control = keycode 63 ?

Vincent