Follow up to "measuring space between elements"

follow up to previous post: Measure Spacing Between Elements

Question: If I want to see the distance between object A and object B, I select A (or B), press ALT, and then hover over the other object to see the ‘red lines’. Let say I want to manipulate that distance while keeping my eye on the value- can this be done? Each time I try, I create a duplicate object because I’m pressing ALT! And the keyboard arrows are useless…