Change A Property Of An Item In MdiParent?

Using a plugin architecture, i created a Form Class that holds the Mdi Form. it has menustrip, toolstrip and statusstrip.

child forms are created as class and are loaded into the Mdi Form at runtime.

using interface, i was able to execute subs and functions of a child in the Mdi Form and vice versa.

now i need to change property values.. to be exact, i need to change the enabled property of the toolstrip buttons depending on which child form is activated using the form_activated event of the child form.

the problem i now have is how to change the property of the toolstrip item in the Mdi Form.. should i be using interface on this as well by creating subs in the interface and have the Mdi Form implement this interface?