Tradeskill book 3x__
 

I would like a tradeskill book with 3x__ (any number) so that I can sort down and have my tradeskill line up and be on different columns/pages... I know how to remove the extra Icon and move them to be 3x5 (15 instead of 16 icons) but when I sort it still tries to sort that missing icon and I lose a skill... Would anyone know how to manipulate the knowledge_sort to accomodate this missing skill(s)?

X X X X X
X X X X X
X X X X X

instead of

X X X X
X X X X
X X X X
X X X X

Grateful to any who can help me...
CaffeineBoy