I'm not sure how to use values in a line. This line checks if there is a model named a value that i put in a string value. This is only a part of a script.
if game.Workspace:FindFirstChild(game.Workspace.GameInfo.Boss.Value) then
That should work just fine :) If it finds an object within the Workspace with a name that corresponds to the value of the StringValue object, then the script will continue. Tried and tested just a few moments ago.
http://prntscr.com/907r4a