different sorting on table

Hello,
Is there any possibility to sort tably with your own pattern?
I mean I need a raport which shows items sorted by variant codes from warehouse entry. Not a problem to give sort and group by... but the problem is that variant codes are defined like -10, -9, -8, ... +10 and navision sorts it like -1, -10, -2.. etc.. i created an array to sum quantity for each variant and then can show it in my order... but when quantity is 0 i don't want to show any output at all ... heh so i did lots of groupfooters and i can control showoutput... but I group records by 4 fields (location code, item no, bin code, lot no) so there are too many groupfooters on my report.. and i can't control it because i never know which one field is changed as the last one... ehh