Try using 3DViewStation it has import and export

https://www.designrule.co.uk/kisters-3d-viewstation

Look at this link for an example. This elephant is designed from the cgr format

Elephant

CGR is to protect the designer.

Only send to check the 3D.

Not to copy or modify.

Crossmanager 2019 64 bit converts CGR to STL (and few others). I know it's not STP, though it's good to know there are some options.

.cgr files are CATIA Graphical Representation files. They are light-weight files of CATIA CATPart models that have been reformatted as many small triangles. These are used in CATIA for viewing purposes primarily.

I'm unaware of any software that will convert CGR data into STEP or IGES or any other format.

If you could find the original CATPart file, you can convert that.