Power an op amp when having only higher supplies
If you're trying to output a signal moving a few volts either side of 0V, then you could produce +ve &amp; -ve rails from your +/-24V using a positive and negative regulator, then power any old op-amp of those.

If you want enormous voltage swings on the output, then you could use a high-voltage op-amp which you can power directly off the +/-24V rails.  Don't do this if you're going to put the output in something which can't take such large voltages though.

Or if you're doing AC-only (audio, for example), you can couple the signal via a capacitor and bias things up off you 0V rail.

"High-voltage op amp" in google found me this: LM143 http://www.ti.com/lit/an/snva516/snva516.pdf which will take +/- 40V supplies.

Never used it, don't know what it's like, but there are clearly suitable products around.

You should say something about the type of signal you're trying to handle.