Let's assume you have a DWG drawing with automatic fields, texts or block attributes linking to a specific geometric properties of selected objects (i.e. fields with the Object option). If you now delete the source objects, the dynamic value of the field will lose its link and the field will display only as "######".
With the freeware LISP utility ReLinkField (RLF) you can restore the lost links. If you create a new control object of the same type or if you want to point your dynamic label to a different, existing object of the same type, just type the command RLF, select the label object (text, block) and then select the new source object. You can perform this "link redirection" also on standard, functional links, not only on those broken, lost ones. Neither the display format nor the property type will be changed in the fixed relation link.
An example of such links - different types of labels showing the radius values linked to circle objects. The dependency links are displayed using the FieldLink utility.


You can download the ReLinkField utility from Download and load its VLX file to your AutoCAD using the APPLOAD command.
A sample drawing - see RLF.DWG in the Block library.