There are 3,000 videos on youtube explaining how to use command blocks. It would require a simple redstone clock to keep the command block testing for a player in the area and then another command block powered by a comparater that actually teleports all players within 25 blocks to the new location..
after you build the clock here are your commands.
testfor @a[r=25,name=!jetace97]
tp @a[r=25,name=!jetace97] x y z
ITS VERY IMPORTANT TO USE name=!jetace97
If you dont you will NEVER be able to get close enough to work on your command blocks again.