It is possible to create a mapkey that will switch focus and activate an open window from a list of open Creo models (win1, win2, ....). If you only have two windows then it is possible to make a toggle to alternate them. If you have three or more then you will require a mapkey for each window.
I suspect you want to cycle through the open windows with a single mapkey and that is not possible using only a mapkey definition.
Are you aware that the UI has a list of current windows available for selection? You can make a mapkey to present that list for selection pretty readily and try it out.
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Specialists in Creo Parametric