it's possible using the screen editor. but depends on how you want to view it. If you only need it in the script use the mc.mcToolGetDataExDbl(inst, toolnum, "Length") LUA API call. for putting it in DRO, Label or Text box you can use the scr.SetProperty(componentName, "Value", toolLength) API call.
mayb easier to do in screen editor if you knew which pound var numbers were associate with tool lengths in the table.