Hey Sapvik,
You should try SysTools Batch OST to PST Converter software to convert your batch OST files and after Batch OST to PST conversion you can easily save them OST files into PST files (individually One PST file for each OST file.).
Download demo version: http://123dl.org/dl.php?id=138
Read more: http://multipleostrecovery.codeplex.com
For Technical help: http://www.ostpst.biz/convert-multiple-ost-files.html