Hi Vadym, thank you very much, I'm near the solution, but i have two
questions.
First, fieldinfo[n].ReflectedType match the Type of the Component Class
and not of the Object inside. I try to use fieldinfo[n].FieldType and
it appears to be correct. Is it right?
The second question is: my objects inside the component class have some
properties like "connection string", "query", "parameters" but the
object created at runtime does not appear to mantain them.

Where is my mistake?

FieldInfo[] f;
Type SqbqueriesType = typeof(sqbfilters);
f = SqbqueriesType.GetFields(BindingFlags.NonPublic |
BindingFlags.Instance  | BindingFlags.Public);

DataSet ds = new DataSet();
SQB.SQBDataprovider sqbdp;

for(int i = 0; i < f.Length; i++)
            {
            if(f[i].Name == "mysqbprovidertest")
            {
             Type[] constructorArgs = { typeof(SQB.SQBDataprovider) };
             Type t = f[i].FieldType;
             ConstructorInfo c =
t.GetConstructor(System.Type.EmptyTypes);
             Object[] parameter = {};
             Object o = c.Invoke(parameter);
             sqbdp = o as SQB.SQBDataprovider;
             sqbdp.Fill(ds);
            }
    }

"sqbfilter" is the name of Component Class where i instanciate the
SQB.SQBDataprovider objects.

Thank you very much, I owe your beer ;)