How to return to the original directory after invoking change directory in DOS batch?

I want to create a batch file, batch.bat, that accepts 2 mandatory arguments:

• %1 represents a path relative to the current directory.
• %2 represents a filaname.

Assume the current directory is father\me\.

User can use this batch as follows:

• batch child/grandchild log
• batch ../brother log

The job description of batch.bat is as follows.

1. Moves to %1 directory,
2. Iterates all *.tex file in the %1 directory.
3. Save the result in the directory before moving.

The following is the incomplete code:

rem batch.bat takes 2 arguments.
cd %1
dir /b *.tex > <original directory>\%2.txt

How to return to the original directory after invoking change directory in DOS batch?