http://www.jemsite.com/tech-setup-a-...-diagrams.html
should be: 2CL2-B BRIDGE HEIGHT ADJ. SCREW
unless i'm mistaken, may want to check the year and check Ibanez'z site.
Your local music shop should be able to order you one, tell em whats up and give them the part#. They are around $7 a piece.