inventory_line_seperate_code/views/stock_inventory_line.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
	<data>

        <record id="view_order_add_code_form" model="ir.ui.view">
            <field name="name">view.order.add.code.form</field>
            <field name="model">stock.inventory</field>
            <field name="inherit_id" ref="stock.view_inventory_form"/>
            <field name="arch" type="xml">
                <xpath expr="//field[@name='line_ids']/tree//field[@name='product_id']" position="after">
                    <field name="product_code" read_only="1"/>
                </xpath>
            </field>
        </record>

    </data>
</openerp>