Look to use
ssget to create a SelectionSet of blocks with name 3042RD (DXF Group 2), iterate through this SelectionSet (plenty of examples of how to do this on the forum) and, for each block in the set, iterate through its attributes (again, examples on the forum or on my site
here).
If an attribute with Tag String (DXF Group 2 of Attribute) equal to "APPROV" is found, update the attribute with the correct value (DXF Group 1 of Attribute).
To determine the value to use: look at the
DWGNAME System Variable (use the
getvar function for this) and use the
substr function to get the correct character.