You can weight ranges in Pokerstove by taking out some of the possible combinations that make up each individual holdings.

For instance, if you though AA was 1/3 as likely as KK in a hand you will give villain this range:

AdAh
AdAc
KdKc
KdKs
KdKh
KcKs
KcKh
KhKs

You do this by clicking Preflop for each individual player, then clicking the certain hand then editing the suit possibilites.