[Serusers] fr_inv_timer_avp on the fly....

[sip]

Can anyone think of a way, perhaps using AVPs, perhaps using a custom module,
that I might do something like set fr_inv_timer_avp on the fly to a value
pulled from the database? 

I was looking at the AVP commands, and I couldn't figure out a way of grabbing
a number of seconds from the DB (that part's easy enough), storing it into an
AVP, and then storing the value from that AVP into fr_inv_timer_avp.  

Now, storing statically is easy enough... at the top of my ser.cfg, I have:

modparam("tm", "fr_inv_timer_avp", "inv_timeout")


And off inside the cfg, I've got:

avp_write("i:45","inv_timeout");  


... to write a static number of 45 seconds to the inv_timeout. That works. 
I'm just trying to think of a way to make it dynamic, storing a value for that
number of seconds in the DB, and retrieving it on a per-user basis (so each
user could set his individual timeout values should he so desire). 

Maybe I'm just not thinking about this correctly. Anyone have a direction I
could try? 


N.