How do I pass an "out int" parameter in BizTalk orchestration?

I have a method written in C#:

public static void MyMethod(string myString, out int myInteger)
...

In BizTalk orchestration I am declaring one variable as an int32 and setting it to "0".

When calling the method with this variable I get the following error:

Cannot convert from 'System.Int32' to 'out System.Int32'

My question: how do I declare an "out int32" in BizTalk Orchestration?

Or how can I manage to call this method that requires an "out int"?