It would help if you said what data you were trying to get. Based on what you have said you need to use one of the postbit hooks. (Off the top of my head something like postbit_display_start would do).
- What code are you using to get the data?
- Is any data actually returned? (Run a var_dump() on the variable which you are using.)
- Try manually setting the variable in the plugin to test it and seeing if you can see it in the postbit.