Setting A Dimension Line A Particular Distance from Objects
Look into the DIMEXO System Variable [= DIMension EXtension-line Offset from definition points]. In model space, the value will be multiplied by the DIMSCALE System Variable for the on-paper offset distance. To my way of thinking, 0.625 inches [5/8"] is a very large offset if they mean that as the on-paper amount -- it's very small at 1/4" scale at model size, but not after DIMSCALE accounts for that. The default is 0.0625 [1/16"] -- is that what they mean?
Kent Cooper, AIA 
@dmfrazier wrote:
"I was asking HOW to enter dims of a specific distance from the object."
After another read, I don't think DIMEXO is the dimension variable you are looking for.
In general, AutoCAD will prompt you for a point which determines the location of the dimension line. To my knowledge there is no dimension variable that sets this distance automatically. The closest thing to this that I can see is Baseline Spacing ... but this only affects the distance between dimensions and does not set the location of the first baseline dimension or of a single rotated or aligned dimension.
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Ah.... I was reading the original question as being about extension-line offset distance from the object [that's one way of looking at the distance of the Dimension from the object], but I can see that they may well have meant the position of the dimension line instead. [In that case, 5/8" doesn't seem unreasonable.] No, there's no variable for that, just the one for spacing between them in the Baseline option [DIMDLI System Variable = DIMensions: Dimension Line Interval].
Kent Cooper, AIA
Just for future reference, to get a dimension a set distance from your objects in PS, draw a line along the outside of the object, offset 5/8", snap to that line with your dimensions. Erase the construction lines.
You could also use xline command, offset option. Or rectangle, surround the object and offset, erase, etc.
GrantsPirate
Piping and Mech. Designer
Always save a copy of the drawing before trying anything suggested here.
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If something I wrote can be interpreted two ways, and one of the ways makes you sad or angry, I meant the other one.
@GrantsPirate wrote:
Just for future reference, to get a dimension a set distance from your objects in PS, draw a line along the outside of the object, offset 5/8", snap to that line with your dimensions. Erase the construction lines.
You could also use xline command, offset option. Or rectangle, surround the object and offset, erase, etc.
I would suggest another way that doesn't require any temporary object.
Turn Object-Snap Tracking on [OTRACK icon, F11 key, read about AutoTrack in Help for possible version-related variants], and have running Object Snap on with some mode(s) that will be present on things you're dimensioning, such as END, MID, maybe INT. In the Dimension command, when it's asking for the dimension line location, hover over something you want the dimension line to be 5/8" from until it "latches" onto a midpoint or endpoint or whatever, drag the cursor out in the direction you want and watch for the alignment track to indicate it's tracking in the right direction, and type in 5/8 [or .625] to get the location that far from that OTRACK base point in that direction, which it will then use for the dimension line location. It takes a small amount of getting used to if you haven't used Otrack, but it's very effective, and this is just the kind of thing it's designed for.
The one situation in which that won't work is if the dimension-line offset direction is not on some multiple of the Polar-tracking angle increment that the alignment track will lock onto, but in most cases [dimensioning orthogonal things or common angles such as 45 degrees] it will work fine, and you can set that increment if you have particular unusual angles that you use.
Kent Cooper, AIA