Batch Macro : Pass the output of one iteration as input to the next iteration

Hello,

I have couple of doubts on Batch Macro:

1. Is there any easy way to see output of each individual iteration in a batch macro. ? This will help me in debugging.

2. I want to pass the output of one iteration as input to the next iteration. Is this possible ? 

My first iteration will look into the entire ColA, and do something to it. Then the second iteration will look into the entire ColB and does something to it and so on.. . But each iteration should take the output of the previous iteration as its input.

I want to handle each column separately (meaning I do not want to handle all columns in the same iteration), and hence this doubt.

Thanks

Antony.