Sorry, I'm just being a trouble-maker. My point is that at some point there will be a minimum set of requirements for getting this to work, and I believe downloading an exe is probably that limit. Maybe do a search for a Java library that can do it for you?
I tend to avoid downloading software from anywhere except the 'official' site or somewhere like Tucows. Not 100% safe but I've been OK so far. If winrar ships as an exe I wouldn't trust it from another site, so I wouldn't go looking for a zipped version.
And a zipped version of winrar strikes me as kind of wacky.