ICenroll - processing String returned by createpfx()

Hello,

Does anyone used createpfx from ICenroll and successfully used created
String?

The problem is that createFilePfx works OK and it's possible to use
pfxs created this way, but when I try to do the same with createpfx()
and save in file it is impossible to use it :/
I'm going crazy trying to convert String returned by createpfx() into
byte[] using System.Text.Encoding.Default.GetBytes() and write it on
disk, but with no success :|

Regards,

Rybasso

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