Hi,
Do you want to use talend "Dynamic Schema" ?
Please see this KB article on talend help center
How to process changing data structureIn addition, for file type, so far only tFileInputDelimited ? tFileInputPositional support for "Dynamic Schema".
You can go to this file: <Talend Studio install dir>/plugins/org.talend.core.tis_x.x.x.rxxxxx.jar. Unzip this jar to a directory, and you will see a file call supportDynamic.txt under resources folder, the file lists all the components support the dynamic schema in the current version.
Best regards
Sabrina