opening unigraphics .PRT file from vb

hi again guys!i've been searching for the answer to this q but no luck ever since

i want to open a unigraphics file (a cad file) from vb aka like an automation maybe using common dialog to browse the file and select it then open unigraphics to access the file.its like the pics below
http://www.geocities.com/infiniume/1vb.bmp
also i would like to open existing word file the same way as above.any suggestion guys?oh i'm using unigraphics nx2 , microsoft word 2000 and vb6.

sorry bout the silly pics.the command button was suppose to be 1.open existing unigraphics file 2.open existing word file

thanks!hope someone can help.