No, because I do not know what .idx has to do with a 3d cad
The file extension .idx usually denotes an index. Such is created by various programs and uses. Do you want to open an IDX file, you must use for each matching application.
Most references an IDX file to a database, because the index is intended to speed up the search in a database. You can open a file IDX usually only when you access the program that the IDX file created.
Which program should open your .idx file?
IDX Info exchange is possible from CADENCE/ALLEGRO to PTC CREO PARAMETRICS/SOLIDWORKS that I know
IDF info exchange is possible from CADENCE/ALLEGRO to PTC CREO PARAMETRICS/CREO ELEMENTS DIRECT that I'v tested
This is a thesis on ECAD-MCAD collaboration https://www.theseus.fi/bitstream/handle/10024/72206/Valkky_Markus.pdf?sequence=1
It talks also about IDX format