It depends on what you need the delay for.
Does it need to be precise, or is it just a minimal delay before continuing with some action?
Do you want to be doing something else while waiting for the delay to expire?
The simplest solution is to calculate the duration of an assembly loop over some "nop" opcodes, perhaps with a calculation so you can adjust it for different us delays.
None of the code in Dynamic C related to microsecond delays applies to the Rabbit 6000, so you'll be on your own to figure out the necessary timing to get the result you're looking for. I'd recommend toggling an output pin before and after the delay code and measuring the pulse with a scope or logic probe.
It's also possible that Timer B or Timer C could be useful. I know they can pulse output pins with durations in the microsecond range, but you might be able to connect an ISR that sets a global flag when the delay has passed.