Hi Grant,
I'm not familiar with the computer in question, so I don't know its power requirements. If it just takes a single AC or DC input from the power unit it should be easy to find a suitable generic replacement over here. You just need to check the voltage and current ratings, type and polarity of connector, and whether AC or DC. All of this information is normally found on the labels.
You could go via Dell, but be warned that they're likely to charge much more for one of their branded units.