Can you please tell me if this is doable, and how could I do it ? I can access to a Windows computer if needed.
Yes it is doable, with the caveat you have a 1/3 or 2/3 duty as mentioned above.
You need Wincupl, to compile boolean equations to JED and then a Device programmer to pgm the 16V8.
WinCUPL can run command line, which may help portability ?
If all you are doing is /3, you could look at other CMOS programmable dividers ?
eg the widely available HC161/HC163 can divide by 3 with an upper Qn connected to /LOAD, so the counter goes 14,15,0,14,15,0... for divide by 3.
Addit: If size matters, you could find a small MCU that has a CLK out option with /3 choice. Still needs programming, but it will be smaller than a 16V8 or CMOS counter.