startup autoexec type file? (to set resolution mainly)

I installed SliTaz on one of my old PCs and want to issue some startup commands. In particular xrandr to change resolution and numlockx to turn on numlock.

I've tried .xprofile, it doesn't use that (verified by trying to touch a file).

I'm new to SliTaz but somewhat familiar with Linux from using Bodhi(ubuntu) already, but bodhi has its own distro-specific startup file so I'm not familiar with more generic solutions...