B737 Captain is barred by MEL from accepting and aircraft with an inoperative wing light due to the requirement to deice; although Maintenance and the Duty Officer attempt to talk him in to it.

Narrative

Copilot found inoperative left wing illumination light on preflight; in addition de-icing would be necessary for frost on wings upper/lower surfaces. Contacted dispatch & Maintenance Control for action. Maintenance Control wanted to apply MEL 33-7b which would be acceptable if we didn't have to deice. Both the MEL and flight handbook deicing procedures require operating wing lights. Maintenance Control said their books didn't require the lights. I contacted the duty officer and discussed it with him. He stated that in a conference call between himself; Maintenance Control & Dispatch that they felt it would be ok to deviate from that procedure. I again stated my position that wing illumination lights were required by the checklist and procedure and that I would not deviate from established/written procedure. The Duty Officer then stated that Maintenance would fix the light and that was the end of the discussion. To make it very clear here; my co-pilot and I followed all procedures and policies governing our job. The problem was the pressure I felt from Maintenance Control for misapplying a MEL when it was crystal clear to that MEL 33-7b could not be applied in this instance and was not; but the words 'we feel you can deviate from this procedure because of the intent'; is very troublesome to me.