full/partial query

I currently backup a small file server using star and fssnap as shown in the 
star man page. Thanks Jörg for this example :)

I follow the modified towers incremental approach as described in Unix Backup 
and recovery, C.Preston, O'Reilly..

thusly

0 3 2 5 4 7 6 1 3 2 etc

giving me monthly 0's and weekly 1's and a reliable mix in between.

The 0 is large enough to warrant burning a CD for the dump and I also choose CD 
for level 1's. The rest are uploaded.

The intermediate increments are generally quite small but i've noticed that if I 
  create a pattern to exclude.....

EXCLUDE="-V pat=\*\.mozilla/\*/Cache/\*"

and drop this in the mix it drops my backups down CONSIDERABLY! Each user has 
around 23MB of hashed Cache files that I consider not worth backing up.... not 
when I would like to upload to numerous places and the inclusion of said files 
makes a dump of 85MB instead of 7MB.

CDs are used for 1 and 0 levels anyway, so I leave them in, so there is a weekly 
dump of the caches...

I notice though, that adding an exclude pattern makes star run in partial dump 
mode as opposed to full when 0 and 1 are used and makes appropriate entries in 
tardumps....

I was hoping that a level 3 partial would reference a level 0,1 full backup but 
this is not the case.

Is there a safe way to cheat this?

Can i achieve what I want by any other means?

Thanks very much

Rob