Identifying Objects Problem. Help?

I'm making a script that puts a zombie in a random position.

local windownumber = script.Parent.window.Value -- this is in the zombie, a string value
local window = game.Workspace.windownumber -- find which window to go to

My question is, how do I make it so local window = game.Workspace.windownumber does not think it's looking for the object called "windownumber" in the workspace, but to look for the value's name, not "windownumber" the object?

To search for a string, do this:

game.Workspace["name"]

or

game.Workspace:FindFirstChild("name") -- or, :WaitForChild()