Tap tempo on a Behringer DR400 Reverb/Delay (re-housing)

[etorex]

Hello everyone! I'm in the middle of a process of re-housing a Behringer DR400 (a good Boss RV3 clone).
For being my first project ever (apart from turning a wah into a volume pedal, but that's even more basic stuff), i'm pretty ahead with the process of re-wiring and i just need to adjust it in the metal enclosure.



Anyway i was wondering, since you would need to hold the switch to enter the tap tempo mode, if that would be possible to have a separate switch just for tapping, and how should i approach this problem.
The original switch was the classic Behringer one, squared with 4 pins, and i mounted a momentary SPST using just two of the 4 connections (the left ones). Any idea on how the second switch should be wired?
Thanks for any possible advice!