Cnvat credit

Dear Sir

Iam working in a tyre company having sales & service we have a service centre, there we do service for vehicles like Wheel Allingment /Wheel Balancing / Water wash / etc.. we are going to purchase a machine on CST Basis and also on Excise included in bill can we issue C FORM For the puchase and also we have service tax registeration can we credit the excise value in CNVAT Credit with service tax payable.

Kindly reply me its urgent

Kindly do the needful

Thanking you