If you're talking about any old humans fighting Ithklur, then you could just pick a suitable [e,g. currently existing merely as a set of randomly-generated string of numbers] world along the Hiver borders and let it just happen to be one of the forty-odd human seeded-by-the-Ancients homeworlds.

But if you're talking about it being *Imperial* humans fighting Ithklur, then I think you're out of luck. I'm pretty sure it's canon that the Empire and the Hiver Federation (and thus the Ithklur who weren't jump capable prior to Hiver contact) have never been in direct conflict.