Encryptipn Decryption from a Java generated key

I have a Triple DES Key generated by java code from a third party vendor. It is a 3 part key.
We need to use this key in our VB.NET application.  When I try to combine this key and use it in my app
'Dim desTransform As ICryptoTransform = desCrypto.CreateEncryptor(EncryptKey(Key), EncryptIV(IV))' gives me an error ' Specified key is not a valid size for this algorithm)
I am new to cryptography and do not understand the algorithms well. How can I use the java generated key in our app for encrypt/decrypt.
 
Any help will be appreciated.
 
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