Hei, I didn't know now we can really get rid of assemblies! Great!Unfortunately the bottom line of the article seems to be: "yes, now you could, but you still better not". Too bad.

Thanks a lot, footballism.

Edit: I didn't see your question.
The task at hand consists of updating cross references in a document base whenever one of the documents is changed.
Each document describes a sub-assembly (in the mechanical sense), each composed of several parts. In a certain sections of the document structure, I am to find the part number and update some info.
90% of the entire expression deals with the document structure, so it never changes. The only part that changes each time is the part number affected.

If you really want, I can post the expression, but it would be worthless without a description of the document structure.