excel - Local (workbook-specific) functions without using VBA or VSTO -

i looking way create workbook-local functions in c++ (unmanaged). vba not appropriate use case. unfortunately, that's way know of create workbook-local function. (i'm not terribly familiar vsto, there may way there, cannot used managed code this.) know how create functions xlls, , know how create automation addin exposes functions through idispatch. however, both of these seem global functions only.

does know way this?

worksheet != workbook

i don't know of way create worksheet-local functions.

in vba expose functions need standard module (.bas) without option private module option set, exposing public function - function usable in every worksheet of workbook that's containing it.

a worksheet class module, , lives object instance: public function members therefore not usable worksheet functions.

functions workbook-local, not worksheet-local.

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now, that's meant anyway, given add-in approach being referred creating "global" functions, available workbooks.

as @rubberduck hinted, creating code via vbide library doesn't require elevation , security settings tweaking if you're extending vbe itself. this might help (it's entry point add-in @rubberduck , working on). add-in edits, deletes , adds code in vbe living, , doesn't require tweaking macro security settings.