[2005 + VB6] Help with encryption/decryption

Because of some interoperability problems with a VB6 program I need help decrypting files that have been previously encrypted (and viceversa) using either the EzCrypto class or OCX for VB6 that supports several hash and encryption algorithms like Rijndael, MD5 or RC2.

I don't know too much about encryption, and have failed in my attempts of adding support for this because of both the key and IV properties.

The EzCrypto class and OCX can be found here and here.

I wonder if anyone here has worked out this thing already, or else, if anyone with experience on encryption could lend a hand.