In the old days, we had macros, Grip, user function. Today we use the .net framework as the API for NX. There are lots of technical details I can't explain, like using different languages, but at the basic level, you can use vb.
A journal is just a basic vb program.
You can record and play journals - like super-macros. This is similar to vba in MS Office applications. If you do this a lot, turn on the Journal tool bar.
You can also write or edit a journal to do more advanced things like this one does. IT uses functions to ask for old and new text, cycle through all the selected objects, and rename them. This is where your vb class will help.
There are several examples in the installation in the folder UGOPEN/SampleNXOpenApplications.
That should be enough to get you going :*)
Mark Rief
Product Manager
Siemens PLM