PARMmenu.xml

<?xml version="1.0" encoding="UTF-8"?>

<menuDocument>
    <menu>
        <subMenu id="open_in">
            <label>Open in...</label>
            <insertBefore />
            <context>
		        <expression>len(kwargs["parms"]) > 0 and kwargs["parms"][0].parmTemplate().type().name() == "String"</expression>
	        </context>
            <scriptItem id="batch_tex_convert">
                <insertAfter />
                <label>Batch textures convert</label>
                <scriptCode>
<![CDATA[
import os
import batch_convert

path = kwargs["parms"][0].eval()
if path != "":
    path = hou.expandString(path)
    path = os.path.normpath(path)
    path = os.path.dirname(path)
    batch_convert.runGui(path=path)
]]>
                </scriptCode>
            </scriptItem>
        </subMenu>
    </menu>
</menuDocument>