You can set two arrays with the same index for the correspondent coordinates.
Just like this:
setarray @x_axis[0],150,158,163,173;
setarray @y_axis[0],184,182,189,199;
set @map$,"prontera";
set @rand,rand(getarraysize(@x_axis) -1); //-1 prevents the rand() do get an non-existent array index
warp @map$,@x_axis[@rand],@y_axis[@rand];
Think this should work.