There are tools available that can export the conversations from WhatsApp CRYPT archives and save them as HTML. From that you can create DOC document using Microsoft Word or similar word processor that allows users to save HTML to Word document format.
Convert WhatsApp encrypted backup (original) to Microsoft Word document (prior version 2007).
We have found one software suitable in our database for this conversion.
Articles and other information relating to crypt into doc conversion:
How to convert WhatsApp CRYPT files - Decrypting WhatsApp message databases
Microsoft Windows software - convert crypt to doc on Windows
A database extractor for WhatsApp Messenger
Convert from crypt file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.