Question: How to best share data between maple worksheets?

We create a lot of Maple documents, and would like an efficient way to share data amoung documents. Some documents rely on the results of other Maple documents.

I have experimented with DocumentTools:-Retrieve. There is an example in the help pages for this that I can run, but for some reason I don't understand, the example uses "L6" as the label for expression to retrieve. In the document referred to, the label is (1).  I can't find L6 is the document, and the example doesnt work with label set to "1". So is there some method to set a label that DocumentTools:-Retrieve uses? If we could create meaningful lables, perhaps that would be a good method for us.

I can see that I can also use the menu option insert>reference and get an expression from another document. I assume that this is a one-time insert. If the value changes on the source document, there is no way to update. There is also nothing shown in the worksheet to show where the expression came from, so unless you add comments, there is no tracability.

Another similar question:

We may have a group of related documents. We would like to have each document be able to export data to a central file (or database?) What is the best way to do this? I could use ExcelTools:-Export  and assign each document a tab or address in the central file. Is there a better way?

Thanks.

Mike