Created Unassigned: Regex expression for parsing BODYSTRUCTURE [2444]

Hi,
I had some issues with parsing the BODYSTRUCTURE, when its more complex.

Changing Line 31 in Expressions.cs from

```
public static readonly Regex BodyStructRex = new Regex(@"BODYSTRUCTURE (\(.+\))");
```
to
```
public static readonly Regex BodyStructRex = new Regex(@"FETCH \(.*BODYSTRUCTURE \((.*)\).*\)");
```

solved the problem.

Best regards,
Michael