NHibernate and operator overloading

public class Version
{
    public byte Major { get; set; }
    public byte Minor { get; set; }
    public short Build { get; set; }
    public int Revision { get; set; }

    private long NumVersion
    {
        //get {}
        //set {}
        //Some logic that make Int64 number that represents this verion
    }
}

Suppose I want to be able to write queries like

Where<Product>(t=>t.Version > new Version(1,2,0,0))

In Product table I store only Int64 NumVersion field, so Version property is mapped as component, and currently I query it like Where<Product>(t=>t.Version.NumVersion > new Version(1,2,0,0).NumVersion)

In C# I can 1. Overload comparison operators, 2. Make it implicitly casted to long like:

public static implicit operator long(Version v)
{
    return v.NumVersion;
}

This will allow me to compare Version objects, but how to make NHibernate understand this and generate proper SQL ?