DOS & WP 6.0 Dates

I am currently checking for a forged document. I need to provide the date that the WP (Word Perfect) 6.0 file was created. I cannot use the standard DOS 6.22 or WP 6.0 dates. I need to be able to verify the date by viewing it within the file itself.This is normally done with a hex editor. But I cannot find the date anywhere within the WP documents. How does WP and DOS know the date the file was created? Where is the OS obtaining the date? Let me know if you have any ideas.