Dynamic Indicator Variables?

[Nicholas C Weber]

How can I reinitialize an indicator's period based on the output of another indicator's handle? Would I create the int/double on the oninit tab, or inside the oncalculate tab? 

Would I copy the handle/buffer over to OnTick and calculate the period variable and return it back to oncalculate?

Edit: I did some searching and apparently the function is capable in Pinescript. There's gotta be some way to make this functional in mql5.. 

[Nicholas C Weber]

Could I declare handles of the source  indicator of the dynamic variable and the destination  indicator of the dynamic variable on global and then copy their buffers to oncalculate and oninit?