[Discuss-gnuradio] dynamically changing input index of selector block

[Janek]

I'm trying to dynamically/automatically change the input index of the 
selector block based on the output of a square wave.  Normally one would 
use a variable block, but I need it to automatically change without a 
user's input.  How can I connect the output of the square wave block to 
the input index field inside the selector block?

Thanks,
Jacob