As per my understanding , You want to pass a variable to DFT and iterate DFT on the basis of that variable if i am right
you can define a variable like counter set it initial value and then use this variable in for loop container like
put values like this in FLC .. Initail Exapression: @counter==0
EvalExpression:@counter<10
AssignExpression:@counter=@counter + 2
Regards
Ashok