I usually use a villain's VPIP and PFR figures in HEM aswell as 3-bet % etc. An example from Harrington on Online Cash Games: 6-max
Villain opens UTG to 3.5x and we have ATs on the BTN. Villain is a 16/12 with a 3b % of 4. Looking closer at his stats tells
us he opens 8% from UTG, which represents 2 possible types of ranges:
Range 1: 77+, AJo+,AJs+, KQs,JQs, JTs.
Range 2: 22+, AQo/s+
Vs Range 1 we have 37.67% and Range 2 we have 39.5%
Range 2 is better as we are less dominated and in more flip situations. In determining a range we need to be watching our opponents and taking notes to see which hands he's taken to showdown to determine which of the 2 types of rnages they can have. With odds
of only 1.4-1 and 2 people yet to act, this makes ATs a fold vs both of villain's perceived UTG opening ranges.
To answer your question more directly, you need to look at your opponents stats and the hands you've seen them showdown in order to accurately determine the range of hands he could have in a given situation.