Naming output file given specific field in input file header - spring-batch

Question

I am relatively new to Spring Batch.
I have an input file with a header. This header contains several fields, one of which I am interested in (YYYYMM data).
Here is my config for this :
<bean id="detaillesHeaderReaderCallback" class="fr.generali.ede.daemon.batch.dstaff.detailles.DetaillesHeaderReaderCallback" >
<property name="headerTokenizer" ref="headerTokenizer" />
<property name="fieldSetMapper" ref="fieldSetMapperHeaderLog07" />
<!-- need to write moisComptable to ChunkContext -->
<property name="chunkContext" value="#{chunkExecutionContext}" />
</bean>
<bean id="headerTokenizer"
class="org.springframework.batch.item.file.transform.FixedLengthTokenizer">
<property name="names" value="dummy1,moisComptable,dummy2" />
<property name="columns" value="1-22,23-28,29-146" />
</bean>
After which, in the next step of the job, I want to generate an output file whose name is composed of a static part and that header field :
<bean id="fileItemWriterLog07" class="org.springframework.batch.item.file.FlatFileItemWriter">
<property name="resource"
value="file:${batch.coherence.out.path}/DSTAF007_LOG_#{jobExecutionContext['moisComptable']}.txt" />
<property name="shouldDeleteIfExists" value="true" />
<property name="headerCallback" ref="DetaillesHeaderWriterCallbackLog07" />
...
</bean/>
(I have two jobs because I first write to a database, and then read from it.)
As one would guess this doesn't work, the config file is flowed so I get BeanCreationExceptions. But this gives an idea of what I want to achieve.
I have no exception on the ChunkContext (yet ?) but one on the writer resource. Here is the exception :
Field or property 'jobExecutionContext' cannot be found on object of type 'org.springframework.beans.factory.config.BeanExpressionContext'
Does anyone have an idea about how to proceed ?
Thanks in advance.