I would have my mainframe programmer write a conversion for it, and export that to SQL Server. Short of that, you'll likely have to write it yourself. this page ( http://www.simotime.com/datapk01.htm
) explains what you'll need to do -- though it has COBOL programmers in mind, it clearly shows the structure of packed decimal fields.
This ( http://www.emaglink.com/converteToa.htm
) may be worth a look too.
Again, easiest to have the mainframe programmer write a conversion tool for you