Player spawning underground in dimension

Hmm.Make a procedure

When player joins world

IF player is in dimension(Surface or your intended starting dimension)

set local y=255

while get block at (player x,local y,player z):

in loop >>set local y=get local y-1

set local y = get local y+1

teleport player to (player x,local y,player z)

execute command in name of player /setwordspawn ~ ~ ~

all blocks are in the IF statement