make_l10n_input_with_roles_callout

System

TS 6.1 Win2K

I'm trying to customize the configurable author submit workflow.
The out of the box worflow uses make_l10n_input_with_roles_callout function to display the reviewer selection pop-up.
I need to change the reviewer selection from roles file to database.
Where can I find more information about the abovementioned function? (I didn't find it in support site also)
Alternatively, where can I find documentation for writing similar functions on my own?