You mean like a Tanglefoot Bag but it explodes and can entangle multiple targets?
I'm pretty sure you can make a copy of a Tanglefoot Bag in the palette and give it a unique TAG.
Then edit x0_s3_tangle to do something specific if the item used has the unique TAG, or do the regular Tanglefoot Bag if it isn't.
if( GetTag(GetSpellCastItem()) == "unique TAG" )
{
//do this
}
else
{
//do the regular tanglefoot bag stuff
}