Add zero

Hi Experts,

I have one field like MATNR. Its data type is char(18).

Now my problem is I wrote select querry based on matnr. if it is 100 means it didn't retrieve the data from the data base.

So I used to unpack command and adds 15 zero's to matnr and its working fine.

But if the Matnr is 'M-10' means its shows run time error. So how can I add zeros before to the parameter matnr at run time.

Thanks,

Points Assured.