ADRMAS idoc problem

We are uploading the data using LSMW

Step1: Customer General Data + Company code data

Step2: Customer Address Updation using ADRMAS idoc method in LSMW

But When I am doing it Its replacing the other fileds in the

Customer address which are not supplied in ADRMAS idocs

Can anybody know how to tackle this problem ?

Useful answer will be rewarded.

Thanks & Regards'

Sreenivasa Reddy