I have a Magento shop with some configurable products. Those products have 3 configurable attributes from an attribute set and 1 custom option that is set on the configurable product itself (so not from the attribute set).
What I want to do is set the attributes and custom options via an url. So when we send that url to a customer via mail, and he clicks on it, it is already configured (but he can still change it via the dropdowns if he wants).
I know you can do this by adding values to the url. For example:
But this only works for the 3 configurable product attributes, NOT for the custom option. Is this something that can be done (but am I using the wrong syntax), or is this something that needs modification of the code?