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.