[XXE] Using a variable in the file attribute

[Huditsch Roman]

Hi, 

I am trying to reuse a variable within the file attribute of <cfg:read>,
but it seems that my variable doesn't get evaluated.
Here is my code fragment:

<cfg:command name="get-stichworte">
                <cfg:macro>
                        <cfg:sequence>
                                <cfg:command name="pick"
parameter="Herausgeber false Fuchs G.Weilinger Lanner LexisNexis Mohr
Stumvoll"/>
                                <cfg:set variable="foo:autor"
xmlns:foo="http://www.xmlmind.com/xmleditor/namespace/scope/view";
expression="%_" plainString="true"/>
                                <cfg:command name="read-stichworte"/>
                        <cfg:sequence>
                </cfg:macro>
        </cfg:command>
        <cfg:command name="read-stichworte">
                <cfg:process showProgress="false">
                        <cfg:read
file="G:/Gesetzestextredaktion/daten/Stichworte/%{foo:autor}.xml"
encoding="UTF-8"/>
                </cfg:process>
        </cfg:command>

Can you help me on that?
Thank you very much for your help!

wbr,
Roman