R devel - May 2013 - Customizing tab completion for package functions?

Dear all,
I've been searching around for some hours now, but did not find a solution.

Is there a way to customize the tab completion behavior of R?

In more detail. We have a R packages called bayeos. This package allows 
users to access a time series database via XML-RPC directly from R. The 
time series are organized in folders. There is a function in the 
packages called "bayeos.cd" allowing the user to change the "time
series
folder" e.g.

 > bayeos.cd('Local Gateway')
All Folders / Local Gateway /
200004 	parent_folder	..
200224 	 messung_ordner 	 Bayreuth Meteo Board
...

When typing

bayeos.cd('

and pressing tab the filename completion hooks in which gives no 
reasonable completions. So my question.
Is there a way to replace the filename completion by a custom completion 
function just for a specific package function?

Best regards

Stefan

-- 
--
Dr. Stefan Holzheu
Bayreuth Center of Ecology and Environmental Research
BayCEER
University of Bayreuth
Germany