[horde] Disabling a module via a hook

[Mike Place]

Hi,

Is it possible to set a registry value via a hook? Specifically, I'm 
trying to disable certain modules via the result of an SQL lookup. My 
understanding thus far is that preferences can be changed as well as 
returning the results of a hook to various applications, but I see no 
method for modifying information in the session taken from registry.php. 
Could some kind soul let me know if this is possible, or perhaps give a 
brief example of how one might do this?

-mp