In the UK, those switches were only used on the ST1100P and that was the off/position lights/headlight switch. Pic shows the police and civilian switches for comparison.
The UK ST1300P had a completely separate module for controlling the blues and twos etc, and the right hand switch cluster remained the same as on civilian bikes (with off/position lights/headlight switch). From the A4 model, Honda changed it to a system where the lights came on all the time (except pressing the starter) so the switch you're asking about would be redundant, unless re-assigned to other purposes.
If you want to reinstate the light switch to work as on Brit ST1100Ps, the headlight and position light pins are in the red connector block as shown in this diagram... but there's every chance the US pin layout differs a bit.
EDIT: I see the red connector is wired differently in Josh's post and the Br/W, Br/Bu, Bu/W and Bl/R wires don't go to that connector but to a different plug!
If you break the Bl/G and Bu/G loops, and connect the wires to the stray connector, your switch should work the lights. Note that the wire that should go to the Br/Bu connector has a Bl/Br feed to the red plug, all the others are the same colours.