You should be able to import or directly open DEX files in Microsoft Excel and then save the spreadsheet as a Microsoft Access database.
Convert Microsoft Excel spreadsheet file to Microsoft Access main database.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert dex to accdb on Windows
A popular spreadsheet application distributed with Microsoft Office suite
Convert from dex 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.