You can use the 'flex' cord with an adapter.
Obviously you cannot plug a 115v appliance into a 230v supply or it will fail.
The cable will be under lower load at 230volts,strangely enough,than it would be with the same appliance at 115volts. Half the load to be exact.
The insulation is good for a lot higher than 230volts.
Basically, the cable is the same.
If your computer's power supply will take 230volts you could just cut the plug off the flex and put a 230v plug on it to make a tidy job out of it.