I am not familiar with Creo now please can you name me your possible import format types.
My first thinking for converting is to use cad assistant from open cascade.
With this software, it is possible easy to convert JT data.
My ultimate desired format is Creo .prt file. I cannot do that directly in Creo unless I buy the JT extension. So next best option would be anything that Creo can open without losing the data(like STEP, IGES or parasolid). But I keep losing some parts of complex assemblies when saved in one of these formats.
Sounds like your trying to do something quick, there are a lot of products available that will address your situation, including products from Siemens. Perhaps you should look for a free trial to get by your current situation. Trying to work through a series of derieved formats is not going to be very satisfieing.
yes you are right, it is a good point.
I have forgotten to explain if you need more than only the graphic you need other software for it.
You can catch with the tool only the graphic.