Paradox has some internal functions devoted to file import, even for the dreaded MS Excel format.
But I don't think you're going to accomplish that by means of them: you're not working with Paradox, you're working with an application WHICH USES PARADOX TABLES, and that's a totally different story...
I think the only viable solution is asking the firm which has created the software for a import routine: not only is it necessary to have THEM make the routine, since only they do fully know the structure of the Pdox DB that lies under the program, but also you need to have full knowledge of the structure of the Excel files you're going to import/export, and not having too many different types of excel files to import, since each file with a different structure means you need a different import routine...