Update doc status

Suppose I have a doctype name Export file
this file will save two types like SC and MLC

SC can be replaced by MLC like in the new export file doc user will select a previously saved SC no. then all the SC data will come in the current doc and filled all the data. Then user will save new Export File as a type of MLC

The fact is when I replaced a SC file with MLC
Than the SC doc status will be changed as replaced

how to do this.

Maybe you can try to rephrase or question a bit - I am not able to understand what you want to do or where you fail.