Welcome to the forum icebearrick!
I'm guessing you're not intending to take your z-force to a dealer otherwise you wouldn't need to reset the display -- the dealer would certainly do it for you. However you might be able to solve this mystery with a simple phone call to your local dealer. They could probably tell you how to reset it, and they might even tell you what the code means and whether it's anything to worry about. It might be something important to fix before you use the mower further.
Also, this is probably a "no duh" question but have to get it out of the way.. are you sure it doesn't simply mean 45 hours? Especially if one of the symbols you refer to looks like an hourglass.. that's normal for an hour meter and just indicates the ignition switch is in the on position.
Last suggestion is download the owner's manual from the cub website, but often the owner's manual won't have this level of detail. You probably need the service manual for this, which is usually not available for free.
Maybe someone who owns this model will help out here... perhaps "forkz"...
:MTF_wel: