Creating a single <input> type with multiple fields

I have a current project that requires a single input type that needs to be presented as a single field with 3 parts:

[label][op][value]

Where label is the name of a filter, op is either ==, != or NULL and value is an arbitrary operand (usually a string). Ideally the input type will return all three subfields when queried. An example of the type of input I'm hoping to implement would be somewhat similar to a Chrome date field.

Implementing it in CSS, PHP or JS are all the same to me.

Thank you in advance for any help, 405nm