an accessible spreadsheet program?

[Bruins Fan]

Can anyone point me to an accessible spreadsheet program which will  
work with the mac?
I need to use spreadsheets for work, and don't have a viable way o  
doing this, because I'm using my macbook at work an ddon't have excel  
on my desktop windows machine.
Can anyone speculate on what it will take to make Microsoft office for  
mac accesible and whether this will be done?  I ideally need microsoft  
office's functionality at my new job, and can't use it because it's  
not usable with voiceover.
Any tips for any word processing program I can use other than the  
basic text edit?
Thanks, Olivia