I would like to see you tomorrow afternoon.

Literal

Tomorrow [possessive-の] afternoon [at-に] humbly-meet want [but-のですが].

お目にかかる is the humble (謙譲語) form of 会う — literally 'have [you] come within my eye.' Used to show deference when meeting someone of higher status, like a client, senior, or official. Strongest keigo alternative to 会う.