EnsureVisible a treeview node by using the node Fullpath

My application is coded in C#.  I know how to get the path of a node, but how can I EnsureVisible a node using the path?  The following code results in a null value for the selected node even though the path in msFirstNodeFullPath is correct:

trvEquipment.SelectedNode = trvEquipment.Nodes[msFirstNodeFullPath];
trvEquipment.SelectedNode.EnsureVisible();

I have also tried the following:

trvEquipment.Nodes[msFirstNodeFullPath].EnsureVisible();

and...

trvEquipment.Nodes[0].Nodes[msFirstNodeFullPath].EnsureVisible();

REvans