I've written an AutoHotkey script and compiled it into an executable to do it. Hopefully, you're using Windows.
It allows you to define three preset cycle values and jump to them via hotkeys. There's also a hotkey to return to the default cycles value.
I've written up and included some general instructions in the zip. For your specific usage, though, codyw1996, I recommend setting the following:
cycles=20100
cycleup=1000
cycledown=1000
cyclepreset1=100
cyclepreset2=10100
cyclepreset3=20100
If you don't want to read my included instructions and just want the quick and dirty: add those lines to your .conf file, copy the .exe to the same folder, run it and use Shift+F10 to go to 100 and Shift+F12 to go to 20100.
You want to use 20100 instead of 20000 since you want cyclepreset1 to be only 100 and, ideally, cycles and the preset values should all be separated by multiples of cycleup/cycledown. That's because the script uses the cycleup and cycledown hotkeys repeatedly to arrive at the preset values. If you were to set cycles and cyclepreset3 to 20000, it would cycle down 1000 at a time until it stopped at 1000 (since one more would drop it below the target of 100 and be 0, besides), which would be 10x as fast as you want. 20100 allows it to cycle down 20 times to arrive exactly at 100. Alternately, you could set cycleup/cycledown to 100 so that you could use 20000, but you probably wouldn't enjoy manually cycling up or down only 100 at a time.