pasted this request on the shadow forum
http://www.nongkhaimap.com/forum/viewtopic.php?f=2&t=150 but please reply here.

Hi serve.copped,

the spot you have marked on the map in your previous post is correct for the location of the immigration office.
If you are traveling from Udon Thani, then take the exit on Highway 2 to Vientiane and you will see the immigration office on the right hand side a few km's down the road.



Our own map, is currently in the process of being updated and will be available for download shortly.

thanks can now also confirm it is at "C".
close enough to walk if you are just a little bit of a walker.(wear ear plugs and a broad hat)
grab a queue ticket as soon as you arrive.
1 photocopy of four relevant things from passport: tourist visa,latest entry stamp, name details page, and the detail side of that white card that they attach on arrival.
1 decent sized photo
1 complete application form available from there.

and 1900baht will get you 30 days, but no smiles, to get smiles need to go to susan poo in bkk.