Raising of escalation bill to customer

Dear Sirs,

I like to raise escalation bill for the materials already supplied during the previous F.Y. as per the new agreed rate. My question is

1. What type of Excise invoice I should issue?

2. What will be the type of clearance (e.g. Domestic / Special Rate / Removal As Such)?

3. Can this output duty adjustable to account credit ?

4. Will it reflect in the monthly ER 1 Return ? If yes, in which column?

Regards.