Sounds like you've done some rewiring. Now I have no idea how much you know about the electrical system on this bike, or others, so if it sounds like I'm talking down to you or anything, please don't take it that way. I don't know you so I don't know how basic to get.
I linked a wiring diagram below in case you don't have one.
The starter button controls the starter solenoid. The solenoid is really just a heavy duty relay. I'm going to assume you know how relays work. If you look at the diagram, the current flow path for the low power side of the solenoid goes like this.
Battery -red wire- Key Switch -black wire- Solenoid -yellow/red wire- Starter Button -yellow/red wire- Ground
So, the starter button is basicly used to ground the yellow/red wire. In the stock controls setup, the handlebars are grounded. The switch housings are grounded to the bars. The starter button is connected to the yellow/red wire. When you press it, a metal contact touches the switch housing, grounding the yellow/red wire, completing the circuit, sending power through the solenoid and activating it.
Your new circuit should be setup the same. The new starter button probably won't ground to the bars (I don't know how it operates) but the yellow/red wire should connect to one side and the other should be grounded.
On the high powered side of the solenoid, the circuit looks like this.
Battery -thick black wire- Solenoid -thick black wire- Starter
The thick wire that goes from the battery to the solenoid and the solenoid to the starter should not have a fuse in it. If you want to add one you can, but it will need to be much bigger than the 15A fuse the rest of the bike uses.
I hope this info helps you figure it out.
http://oldmanhonda.com/MC/WiringDiagrams/MCwiring.php#class
