A url would be helpful indeed but what you are looking for must be in that select tag element.
HTML name attributes are not always unique but assuming that's the first one with this name you can set the select element into an object this way:
Set objSelect = ie3.getElementsByName("selectedHostId")(0)
If you expand that element, you'll see that it has child elements with option tag.
Option tags have value and also innertext which are not always the same. You have to use the value.
objSelect.Value = "ValeOfOptionElementYouNeed"
The dropdown has an onChange event. You might need to "fire" it in order to imitate a manual selection:
objSelect.FireEvent "onChange"
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