Want to use the Spike Necklace for the DEX +3 and STR +3 but have passed it over because the -6 MND will make you less resistant to spells? Well you can at least use it to enhance your specials with the following macro.
/ja "Sneak Attack" <me>
/wait 1
/ja "Trick Attack" <me>
/equip neck "Spike Necklace"
/wait 6
/equip neck "[original neckware]"
This way when you do sneak + trick you'll have the buffs and debuffs from the Spike Necklace only during the special. Unfortunatly there is no way to do the same with a sneak/trick/WS without using two seperate macros.