If I'm reading this right, you need to equip the items first. Move the item from your inventory to your character's device tray. The device tray is on your character's paperdoll, the screen where you equip your weapons, armor and personal shield. The bottom four slots are your device tray.
Once the item is in your character's device tray it should appear on your number bar in the corresponding 7, 8, 9 & 0 spots. (Or is it 9, 0, -, = ? I'm at work so I can't check) You can move icons in your number bar by right clicking them.
One of the reasons you have to equip them is because you can also equip them on your Bridge Officers.
If that's not your problem, my next guess is that you may have to hit 'P' and drag the icons from the window that pops up to your number tray.