How to auto generate code for salesforce wsdl in sap po

Hi

We are working on salesforce integration, we are sending invoice retreive to salesforce though proxy , in that we are sending PDF attachment to salesforce through soap receive channel using 'keep attachment ' option, but at the same time we need to send the auto generated code for pdf file to salesforce through wsdl 'attachmnentpdf' field.

Please share your inputs, how to send auto generated code for the pdf file to salesforce.