AutoCAD Inventor :: Automatically Mark Parameters As Export

When I bring in a custom content center part or extrude a part I make, I always like to type it as LENGTH=24, thereby creating a parameter called length (instead of d0 or whatever it wants to call it). I then mark it as "export" manually so it shows up in my "custom parameters" tab on my iProperties. I do stuff with that exported parameter in my drawings. Is there a way to make it automatically export?

Or another approach, if I do LENGTH=24, is there an AUTOMATIC way (iLogic, etc) to make a new custom property, also called "LENGTH" that equals the LENGTH parameter?