all a key less entry is a transmitter that supplies the same power as if u were to hit the unlock button, i dont have the specifics on the keyless entry u have but this is the schematic for a 98 (should be the same for u) all u have to do as splice in to the wires u need from the transmitter for this to work. good luck and have fun!
1998 Honda Civic Car Alarm Wiring Schematic
Battery Constant 12v+ Positive Wire (+): White
Battery Constant 12v+ Positive Wire Location: Ignition Switch Harness
Starter Positive Wire (+): Black/White
Starter Positive Wire Location: Ignition Switch Harness
Ignition Positive Wire (+): Black/Yellow
Ignition Positive Wire Location: Ignition Switch Harness
Accessory Positive Wire (+): Yellow
Accessory Positive Wire Location: Ignition Switch Harness
Second Accessory Positive Wire (+): White/Black
Second Accessory Positive Wire Location: Ignition Switch Harness
Parking Light Positive Wire (+): Red/Black
Parking Light Positive Wire Location: In Drivers Kick Panel
Power Door Lock Negative Wire (-): Green/White
Power Door Lock Negative Wire Location: At Blue Plug In Drivers Kick Panel
Power Door Unlock Negative Wire (-): Green/Orange
Power Door Unlock Negative Wire Location: At Blue Plug In Drivers Kick Panel
Door Trigger Negative Wire (-): Light Green/Red
Door Trigger Negative Wire Location: Low In Drivers Kick Panel
Domelight Supervision Wire (-): Light Green/Black (Requires Relay)
Domelight Supervision Wire Location: In Drivers A Pillar
Horn Negative Negative Wire (-): Blue To Gray
Horn Negative Negative Wire Location: At Steering Column Harness
Tachometer Wire Negative Wire (-): Blue (The tach test connector is located under the hood on drivers side firewall.)
Tachometer Wire Negative Wire Location: At Tach Test Connector
Brake Light Positive Wire (+): Green/White
Brake Light Positive Wire Location: At Switch Above Brake Pedal
Factory Anti-Theft System: Transponder anti-theft system, requires bypass module and extra ignition key.