I am not sure exactly what you are using when you refer to the ‘Word Document Generator Library’. Can you provide a link
However, it is probably possible to post-process the document after you generate it, tweaking the formatting for the numbering as you desire. I say ‘probably’ because I am not clear on exactly what you are using, and what exactly is the form of the Open XML markup after you generate it.
Have you taken a look at DocumentAssembler, which is a module in Open-Xml-PowerTools?
DocumentAssembler Developer Center
I am quite sure (although I haven’t tried it) that you could set up the numbering exactly the way you want it, and use a Repeat / EndRepeat to create repeating content, then use Content within that to specify the contents of each list item, and it will produce numbering in the exact format you want.