We use a grid for our game so you can actually see where everyone is.
Now the following situation three pc's attack one target, lets say there all in front of the target, one straight, one left and one right. All three are in melee combat range and can attack the target with a melee weapon.
Two pc's attack the target with melee weapons and one draws out a ranged weapon.
The target chooses to dodge one melee attacker and to attack the other melee attacker. The pc with the ranged weapon has not been attacked this round.
So the question rises: is that pc in melee combat??
Obviously he will be shooting into melee combat and thus gets a -20 penalty, but he's also at point blank range and thus gets a +30 bonus. Moreover he can use his e.g. shotgun, plasmagun or whatever.