Hibernate version: 3.2

Hi everybody and happy new year (not to late ?)
Well I've got a tricky thing to do :

I've got two table T1 and T2, T2 has a FK on T1.
T2 contains dated values. But it contains only the changing values.
Exemple [ 00h00/250; 14h10/125; 22h30/250 ] like a RLE compression.
but we would like to work on non RLE compressed data. So when we do : T1.getT2s() (which is a one-to-many) we would like a list like :
[00h00/250; 00h10/250; 00h20/250; ... ; 14h10/125; 14h20/125 ...] => about 288 elements for a day

And of course I would like to give T1 to save to the DAOs and it saves only the changing values.

And to finish I'd like it to work in HQL too.

I've looked at UserType but it doesn't seam to be what I need.

Any idea ? am I dreaming about something impossible ? I'm sure we can do something intelligent for this in Hibernate !!

No solutions ? I'm pretty sure it can be done in a nice way.