change Combination reference number on invoice to Main ref number

[Mian Waqas]

Hi there,

i have a product with combination , the Ref number are different for main product as well as combination products. if some one buy a combination product, on invoice it will show that Ref number of the combination product. so i want to change the Invoice where it should always show Main product Ref number rather then Combination Ref #.

in simple words:  want the main product Reference number on Invoice rather then the Combination Reference. 

 

Thanks in Advance

[Prescol]

Why not writing the same ref on combinations?