Cross-reference to numbered element in another subdocument

How can I insert cross-reference (with number) to a numbered element in another subdocument in a master document?
The only solution I know is to manually create numbered list. Create a numbered range (in menu Insert->Fields->Other, select Variables, Number range), then use fields of this range to number elements in the list. After that select the number and use “Set reference” (menu “Insert->Cross-reference”) to create named reference to the number. It will be possible to use named references in subdocuments (Insert->Cross-reference->Insert Reference).
But does more convenient way exist? May be it will be better to implement reference exporting and importing (a document can export some references, then another document can import they)?

If the final document is to be electronic in form you may want to consider a hyperlink to a bookmark in preference to a cross-reference for this level of detail i.e., an item in an ordered list. If you are going to print, then a cross-reference will be necessary. I have (thankfully) never had the need to do this, but if I did my approach would essentially be similar to what you propose. It is not the most elegant solution, but it should work. Your approach will depend on how many of these cross-references you require, the nature and size of the lists and list items, and the type of information you wish to convey to the reader at the source point in the text.