Same Counter for two nodes in target structure

[Jwan_]

Dear integration fellows,

I have duplicated the subtree in the target structure. So I have now on the target structure twice the node called DetaglioLinee. Because we need to map different fields from source to target. We have in the node DetaglioLinee a field called NumeroLinea. For each line item the counter increases by 1.

Now we have two subtrees with different mapping, but I want the counter to be the same. Is this possible? Can we copy maybe the occurence of the source field mapped to first subtree and increment it by then? (e.g E1EDP01 is occuring 2 times, save 2 in variable and increment by 1)