rogues and mouse button 4 & 5

Please can you help? How do I make 3 rogues hit the same target...do I have to sap then move closer so all are on the target and I use mouse 4 as - and 5 as =, but it doesn't work with the click through option. How can I set it up? I use a trackball explorer due to limited mobility.
Please can you help

[lax]

In ISBoxer's Wizards menu select Mapped Key Wizard. When it asks what kind of mapping to set up, select "Key Re-map". It will ask for the Hotkey, the Key Combination to send to the game, and which window(s) to send that to. Set the Hotkey to Mouse4, set the Key Combination to -, and specify which window(s) you want it to go to (e.g. Window: All w/ Current). Repeat for Mouse5 sending =

To select the same target, use assist (Alt+A by default)