Created attachment 6418 [details]
PATCH to do it.

Please apply the patch and excect it and check "Test1.xls" and "Test2.xls"
with Excel Application.

import java.io.FileOutputStream;

import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

public class Test {

	public static void main(String[] args) throws Exception{
		HSSFWorkbook book = new HSSFWorkbook();
		HSSFSheet s1 = book.createSheet("Test1");
		book.write(new FileOutputStream("Test1.xls"));
		s1.setActiveCell(10,(short)10);
		book.write(new FileOutputStream("Test2.xls"));
	}
}

have we done this yet?  I thought we did.

HSSFCell.setAsActiveCell()

Please reopen if that doesnot solve your problem. Thanks.