Execute JavaScript from LotusScript agent

How can I run or execute JavaScript code from a LotusScript agent? Specifically, I would like to run the history.replace JavaScript function from a LotusScript agent.

If I understand your question correctly, simply have your LS agent print the JS to the browser and the browser will execute it. For example:
Print |<SCRIPT language="JavaScript">history.go(-1)</SCRIPT>. Do you mean the location.replace method by chance? As far as I know, there is no history.replace method in JavaScript.