Official answer - you can not. Unofficial - take tahoma and tahoma bold from your computer (in /Windows/Fonts) and put it into Windows/Fonts directory of your WM6 device. You'll see hebrew in most of applications. However, it will be הכופה תירבע. So, who tell, that Haaretz are old fashioned because they are still using Hebrew-Logical?
Better, then nothing. If you want full Hebrew support, you should buy localization for WM6 (this one [Eyron's extender] for example).