Forms :: How To Get File Directory Path Dynamically In The Report

I want to get file directory path dynamically with out using directory in database or not hard code like below

the purpose is i need to check image in the path directory if not found i unable to generate report, is there any possible to get dynamically

function CF_URLFormula return Char is
v_handle utl_file.file_type;
v_file_dir VARCHAR2(60) := '/u002/app/applmgr/temp/';
begin
v_handle := utl_file.fopen(v_file_dir, :photo_name, 'R');
utl_file.fclose(v_handle);
RETURN v_file_dir||:photo_name;
exception
when others then
srw.message(100,SQLERRM);
return null;
end;