SAP CPI : Issue with Attachment when we push in multipart/form-data format

Greetings,

Here I have one requirement to read a attachment from SF and push the file to 3rd party system which accepts only multipart/form-data.

I tried getting a file from SFTP and with Groovy script I can able to post successfully to 3rd party system - Script attached ( script9.txt ), but same when I tried pulling file from SF and tried using decode base64 Pallet with same groovy script and it is not working so I clearly understood that Base62 decoded Pallet from CPI is not working in this case.. can anyone help me on this how to push the file to 3rd party system using multipart/form-data format

Regards

Naveen