Thank you for your post.
It is possible to set new Windows credentials using the API. For this you can use the API call:
For this to work, the inheritance for the credentials needs to be disabled (assuming you already have credentials set, this is not necessary). The "property_name" parameter can be discerned by opening the "Settings" page of an object and looking at the HTML source of the INPUT fields. For example the INPUT field for the "Domain or Computer Name" field is "windowslogindomain_". Leave away the "_" and use the rest ("windowslogindomain") as a value for the "property_name" parameter.
Please use this API call with caution.
Sasa Ignjatovic, Tech Support Team