It'll get complicated here. Because you're using the OnExit trigger, you can only write data to one FlowItem at that time. So you have to come up with a logic that knows which sub-part is currently leaving the seperator. You could realize this by incrementing a label (on the seperator itself).
That means after the first sub-part, the label has to have value 1. Your OnExit trigger now has to have a functionality that looks through your rows, skips the first "search result" (where it refers to the current counter value), takes the information from the next row of the PlateNr., assignes the info to the FlowItem's labels, increments the count label on the seperator, skips the first two "search results" in the next run, increments the label, .... and so on until all sub-parts have been processed. Then the count label should be reset to zero until the next FlowItem comes and will be split in sup-parts.
Good luck :-)
// Oh .. should have refreshed my browser. Steven's post is quite what I also wanted to point out
