How can we use UDFs in nx2 or nx3?

Hello. We have a user who wants to know:

<div id="post_message_152">I am working on unigraphics nx2. Recently we updated our
system in nx3.
There is some requirment where we need to use UDF (like
devaloping the mould base). Where we want to call guuide pillar & bushes
same size. So thats why i need udf library. please guide me, what is best way where
I could use UDF.

thanks

mohit uppal
(nyx software design
ltd)</div>