InputField with Matchcode + Any User's text

I have an InputField with a matchcode,

ISimpleTypeModifiable myType=wdThis.wdGetAPI().getContext().getModifiableTypeOf(field);

IModifiableSimpleValueSet values=myType.getSVServices().getModifiableSimpleValueSet();

values.put(cod,txt);

values.put(cod,txt);

values.put(cod,txt);

values.put(cod,txt);

values.put(cod,txt);

values.put(cod,txt);

OK,now i need to give permision to user to insert any text or select one of values in the matchcode. I dont know if that is possible, in my case, if I insert an incorrect value, the application show an error because de value isn't in the list of values.