No, this is not possible. The value you pass to the commandName
attribute is a key and it is not resolved like a normal EL or SpEL expression would be. It is used directly. In other words, with
<form:form commandName="products[0]">
<form:input path="name"/>
</form:form>
Spring will look for a model attribute called products[0]
which it won't find.
The alternative is to put the first element of the list in the model directly with a key you will use in your jsp.
Or you can use JSTL, get the first element in the list and create an HTML <form>
element yourself.