Setting value in word doc

You will have to open the document like,

function main()
{
    var MsWord = Sys.OleObject("Word.Application");
    MsWord.Visible = true;
    // https://learn.microsoft.com/en-us/office/vba/api/word.documents.open
    MsWord.Documents.Open("C:\\Temp\\Word.docx");
}

Refer to https://learn.microsoft.com/en-us/office/vba/api/overview/word/object-model to try and gain access to the objects you need. Hopefully, there should be examples on the internet, most likely written in VB Script, but it should give you a rough idea.