Cenvat credit on imports

Dear friends,

Kindly clarify my doubts regarding availment and utilisation of cenvat credit on imports.

1. Can CVD and the addtional import duty paid (4%) on imports (input items) (based on bill of entry) be availed as cenvat credit?

2.If availed as credit can the above two items be utilised against the payment of basic excise duty?

3.Can the basic excise duty, cvd and the additional import duty be clubbed under the same column cenvat under er-1?

Thank you in advance.