How to access data through dblinks in custom.pll

Hi,

We have requirement to validate data from one instance to other instance. When we are using dblinks in custom.pll it is not supported.Could you pleae let us know how can we acess data through dblinks in custom.pll.

example select code_combination_id from gl_code_combinations@dblink.

When I am using above it is not retrieving anything and it is struck there. If I run same in sql I am able to retrieve the data. I tried to create view tand synonym as suggested in other forum to access data through dblinks still it didnt work for me.