This macro is part of the bibMacros package but can be used without it.
This macro completes the contents of a field in a bibliography item.
It searches for possible completions from the same field in the existing bibliography items. So if for instance you invoke this macro when you want to fill an "author" field, you'll get all authors in turn that you already have in your bibliography database. If you type the beginning characters of the name, you can limit the possibilities. If you are in a "crossref" field, the macro suggests keys.
Put the macro in %b\Macros\LaTeX\, and assign a shortcut to it if you want.
Or download the bibMacros package which includes all BibTEX related macros (and some more).
Macro contributed by Robert <w.m.lgmx.net>