One option is to use Mendix document generation capabilities. These features do not currently enable you to import a Word document, however, you can create a document template that can be used to generate a document with data from your app. See this documentation to get started: https://docs.mendix.com/refguide/creating-your-own-documents
Hope that helps,
An excellent module for this Document Generation for Mendix. You can build your template in Word with mergefields which need to be mapped to entity attributes. Then you can generate (secured) PDF files with your data.
You will need a license but that's is easily worth instead of the hassle trying to implement the same thing in Document templates.