[Contact Form 7] Combining two text inputs

I have a requirement to compine two text inputs into one before submitting the form.

As an example, I have firstname=”Mike” and lastname=”Jones”. When the form is submitted, I would like those two combined into a new variable such that name=”Mike Jones” or, if that’s not possible, inserting lastname into firstname so that firstname=”Mike Jones”

Note that this is a simplified example; the problem cannot be solved by simply having the user fill in the form directly as “Mike Jones”.

…Mike