Another useful tip is to use %* to mean "all". For example:

echo off
set arg1=%1
set arg2=%2
shift
shift
fake-command /u %arg1% /p %arg2% %*

When you run:

test-command admin password foo bar

the above batch file will run:

fake-command /u admin /p password admin password foo bar

I may have the syntax slightly wrong, but this is the general idea.