Sortable Question

Hi,
I was wondering if it is possible, using the sortable ui plugin, to
have a sortable list but certain items in that list are static. For
example, if i always want an item to be in the 3rd position of the
list, and I drag an item from below to above the third position,
whatever was in the second position should jump down to the 4th
position. Is this possible?
Thanks.