Datatype change from NVARCHAR to decimal

Hello Gurus,

Small help required.

I have replicated table from ECC VBUP and it is having datatype NVARCHAR but I want to change it to DECIMAL 6.

Is that possible? Or is there any alternate solution so that I can add one more column "POSNR_1" having all the data of POSNR with datatype  decimal.?

Thanks in advance.

BR

Sumeet