Please read Aditya's post more carefully. The features may or may not
be labeled in a language the CAD operator and operating system can
understand. We have this problem with drawings from China where the
Chinese characters come across as gobbledy-gook. So what may be Extrude
1 to you would be n7 to his people.
Unfortunately SW does not provide user accessible numbering of features
and in fact when you obtain an array of features there is no guarantee
that the order will be the same from one time to the next. Naming the
feautures is the only way, but he is not allowed to modify the file. I
think this problem exists because of the nature of the way objects are
stored and retrieved.
Consider for example what happens if you create an extrude. The first
time you create it it will be Extrude 1. If you delete it and recreate
it it will be Extrude 2 and so on. You can also roll back and create
Extrude 3 prior to Extrude 2 in the feature tree.
The only sure fire way I have ever seen to positively identify features
was written by Phillipe G. as part of his Assygator software from the
now defunct Dynabits company.