I don’t think that what you’re asking for is possible.
The tool you have is security. You want to secure this library with *public exclude
The application needs to run with owner authority instead of user authority and the owner of the application programs needs full authority to the library.
Maybe you could create a small CL program to do the WRKQRY command and make sure that the CL program runs under *OWNER profile and exclude the owner of the program from the financial library and objects.
Create the CL program, then use CHGOBJOWN to change the ownership and CHGPGM to USRPRF(*OWNER).
I’m not sure whether WRKQRY by-passes this sort of adopted authority or not, but it’s certainly worth a try.
Cool – Martin’s answer is closer to what you want – if it works please let us know.