Change message subject created from a job

Hello everybody,

i have a little problem:

i have a job that sends an attachment(pdf) by email.

Sap automatically creates the message subject with 'Job' + job_name + ', step 1' and the file attached have the same name.

If i access to the email with a PDA, it doesn´t recognize the ',' in the pdf filename and i can´t open the file.

I need to know if there is any way of change the standard subject of a message and the filename attached, created by a job.

Thanks in advance

António