Problem with %l variable

There is a button.
Why does it output just ""? For other letters, it seems to work as expected.
I am trying to run an external command using "%l" (in parenthesis) as parameter.

<?xml version="1.0"?> <button backcol="none" display="label" textcol="none"> <label>test</label> <icon1>#newcommand</icon1> <function type="normal"> <instruction>cmd /K echo &quot;%l&quot;</instruction> </function> </button>

Try doubling up the % so it's %%l instead of %l