The initial required steps would be as follows:
1. Expose the part variable from the Variable Table:
2. In Draft, in the Parts List Properties, Column Tab, this variable will be listed in the Properties list which you can add as a column:
But I guess, your requirements are not so simple.
OMG, Really? just for a FAQ; that was such a low hanging fruit, I even wrote a beginner's article on that 3 yrs back right here on the community site:
I use that feature all the time. But what I have done is use the variable L.
Whatever I rename (and expose) to L for any part then shows up in the part list. I use the same column for the Cut_X of sheet metal.
I end up with a column labled Cut 1 that will display either the cut length of a frame member, or L, or Cut_X depending on what applies. Then I have a column Cut 2 that displayes Cut_Y.
The Cut 1 Column is formatted like this
My only glitch is that the frame members don't drop trailing 0's like the Cut_X and L