Yes, No, Maybe
You may be lucky and you should do a little research through your own airline.
NO, you definitely won't get an actual jumpseat in the cockpit, not anymore. You will be asked to wait until almost closing time and if a seat is available in the cabin, you will be given that. The airline you intend traveling with has to have your company on
their "approved" list. You will definitely need your ID as well as all your licenses. The Captain also has the final word. Not sure about foreign nationals. In my experience, only US airline (Part 121/135) pilots were allowed. I know for sure that if you are an American flying for either Cathay or JAL, it is almost impossible to jumpsaet on a US domestic line. I believe it is an individula airline deal and may have changed as a result of 9/11. However, since you work for DHL, this might not be a problem for you. I would strongly suggest you check this out before making any plans.
Back in 2002, I jumpsat twice with United (successfully) LAX/LHR/LAX and it went smooth both times. The only hitch was at LHR the check-in staff did not know or were not sure what a jumpseater was and I got bounced around from desk to desk. Finally, I ended up paying for the taxes and PFC ( the British have to have their money, not so in the US - it's all free) but that was OK, only GBP40 for a Business Class seat worth approx $7000!!!
Second time I knew which desk to go to, what to say and had my credit card waiting. It's amazing what you can do if you know the answers and look the part!!!