Production Order Stock Movement from one operation to another

Dear All,

I am configuring the Production Control on one of my client. I have a Four operation defined in one Route.

i have created a production order with the quantity of 200 pcs and Start Production Order with the 50 quantity in operation 10 and post picking list and route card journal for the operation 10, how can i move the 50 WIP quantity from operation 10 to 20. Because when i click again to Start button this will shows the remaining open quantity in the production order i.e. 150.

Please help me how can i move stock from one operation to another in production order ax 2012.

Thanks