I was wondering how to input sticking in sibelius.  i'm using the manual snare drum sounds, and using the lyric tool to input sticking, but i don't believe that's the correct way to do it- at least it doesn't sound (through my speakers) like it's sticking it the way i'm writing it. 

is this the right way to do it?  or is it absolutely necessary that i buy a midi keyboard?  or is there another possibility with just my computer keyboard?

Unfortunately, the technology hasn't caught up with our hopes and dreams for the capability of the software i.e. Sibelius won't yet take entered stickings and translate them to the proper right and left hand sounds in Virtual Drumline.

You don't necessarily need to use a MIDI keyboard if you get to know the notehead numbers in the template well enough. I assume that you're using the Sibelius 6 VDL template:
https://www.tapspace.com/VDL-Template-for-Sibelius-6-pr-95.html. If not, you'll need that to get the most easy to use experience with Sibelius and VDL.

if you are already using the template, then you'll just need to spend some time getting to know the noteheads for right and left hands. For instance, the Right hand Hit notehead for SNares, Tenors, and Basses is always 0 (zero), Left Hand Hit notehead is always 31, etc. These can of course be found in the ReadMe included with the template. There's a keyboard shortcut for changing noteheads in Sibelius that will make your life much easier. Hold down Shift+Option (Mac) or Shift+Alt (Windows PC) then type the notehead number relatively quickly and consecutively using the top row of numbers. For instance, for notehead 29, you'd hold down Shift+Option then while holding those keys, type 2 then 9 right after it.

Using a MIDI keyboard would definitely be easier, but I know people who use the method I just mentioned and are able to work pretty quickly doing just that.

Hope this helps!