Question: Cylindrical coordinates in Physics[Vectors]

In Physics[Vectors] the operation ChangeBasis exists to change between different coordinate systems (Carthesian, cylindrical and spherical). The cylindrical system uses the third coordinate (_k) as its axis.

As it happens, in my work the axis of the cylindrial system should be the 2nd one (_j). I do not want to reformulate everything as this would become non-standard and confusing. I am wondering whether it is conceivable to "retrofit" the Physics package to allow for that. At issue are not so much the formulae; I can do the transformation "by hand", but that is a bit clumsy and I am looking for a way to have this integrated better in the Physics package so that all other operations (e.g. Nabla) do the expected.

I have looked for and not found something like an "addBasis" command. Am I missing something obvious here? I should add that some of my work happens on Maple 15 (Mac OS X PPC so no upgrade possible); if something like this was added recently I may have missed it, although I do have access to Maple 17 as well so I could use that version for this particular problem. Is the source of Physics actually open?

TIA,

Mac Dude