Meant to put an asterisk on that "safe". "Safe" in this case means both that it puts out enough amps, and that it's the correct brand, etc. Third party chargers don't work on Lenovos, for instance.
But I digress. What does the plug on the end of your AC adapter look like? Is it just the sleeve and barrel, or is there a pin in the center of it as well? Post a picture of it, if that didn't make sense.
EDIT: The rear view image of that PC on the web doesn't bode well. It looks like the power port wants a center pin, which carries that ID information, which, while spoofable, is pretty difficult to spoof.
EDITx2: Since it looks like you need that ID pin, you're back to first or third party laptop chargers.
this might work if the OD of that connector is right. I'm afraid this is going to be a little hit or miss to get this working, though. Can you post the model number of the stock AC-DC adapter? If it can be matched up to a corresponding laptop, then you just have to find a car charger that's compatible with that laptop.