I would recommend doing a google search on trade articles that mention Dell and some other keyword that describes your product. Things like press releases, reviews, articles, etc. often have a quote from a company representative along with their title. From this title you can guess if they are correct person to call.
After you identify a possible contact the tricky part is to get their phone number. Sometime the operator will patch you through to their voice mail. The key is leaving a message that sparks enough interest for a call back. Getting a hold of their email is also good but not as promising as getting a live person on the phone.
Hope this helps.