New valuvation group for existing valuation area - Account Determination

Hi Experts,

Existing Scenario :

-> Plant level valuvation is been maintained

-> Valuvation group code 0001 is assigned for all the Valuvation Area until now.

Req :

I need to set new account determination for a particular material type for the existing valuvation area.

How to achieve the same ?

1.Do I need to create a new valuvation groupcode and assign the same for the existing valuvation area ?

Your inputs will be helpful.

Regards

Prasath