Create a copy of Autoinvoice of Master and Import program ??

Hi Experts,

We are using R12 (12.1.3)

Our client need to make the  (Low) Sales Order Number  and  (High) Sales Order Number in Autoinvoice Master Program, but we cannot make that because Prject invoice also uses same  Concurrent program "Autoinvoice Master Program".

Please give us some lights to achieve the same ..

Please suggests  what will happen If,

Create a copy of Autoinvoice Master Program & Autoinvoice Import Program , made (Low) Sales Order Number  and  (High) Sales Order Number mandatory ?

Thanks