Is that the reason he gave you a no, because of the wind issue? If it is, you can normally add something, but it will have to be engineered to withstand whatever wind velocity they use in that area.
You said he told you that you can't "cut" into the existing structure. Normally if you do that then the home will no longer meet the HUD code that it was built under. If the jurisdiction is strict they might not let you cut anything out of the original structure.
I think you have to ask him the reason he said no and then get back on here and maybe someone can think up a solution to help.

Even if regulations did not affect cutting new openings in the exterior of a mobile home, I would be reluctant to do so. The original framing does not have the extra margins of strength that are in stick-built houses. Plan your addition to use the existing openings. And any additions, lateral and vertical, should be supported independently of the mobile home.