Controlling filename of local copies of PDF document taken from a SharePoint Online library

Question

I have a library of technical documents in SharePoint Online. People need to be able to attach them to emails to send to potential customers but I want to define the filename that will be applied when the document is copied out of SharePoint into the email,
and it won't be identical to the filename under which the file was originally uploaded but rather a concatenation of the original file name and some other fields from the library including the document type and version number.
I only have out-of-the-box SharePoint Online available and I'm a SharePoint novice, but I'm willing to have a go at some customisation if it's not too difficult.

Answer 1

Thanks for the reply Alex!
Certainly, as an example:
Under my top level site Collection:
/subsiteA has been created using the records centre template, and I have a document library: "test docs A" in this subsite.
In subsiteA I have a content type called "Test Content Type"
"Test Content Type" has a column "test column A" which is a basic text column.
When I upload a word document to this library, then open it again, I can see the "test column A" in the document metadata (which appears in Quick Parts).  However, "Document ID Value" does not appear.  If I run the same scenario
on /subsiteB (created using the team site template), Document ID Value does appear.
With regards to {_UIVersion}:
When I turn on an Information Management Policy and enable the Label feature, I can add {Version} to the field successfully.  However, when I upload and open a document from the document library in /subsiteA, the "Label" metadata is inserted
in the word document, however the value is {_UIVersion}, rather than the numeric value of the sharepoint item version (ie, 3.2).  When I do the same against /subsiteB, the "Label" metadata does contain the sharepoint item version correctly.
I installed the "SharePoint Manager 2013 Online" app to the library.  As you say, it looks like the enableparser property is not anywhere to be found.  The only difference I can see is: RootWeb->Webs->subsiteA.WebTemplate = OFFILE
whereas RootWeb->Webs->subsiteB.WebTemplate = STS.
I hope that makes some sense and thanks for the help!