You need 'The question of,' but that would collide with 'to what extent.' Even without it it's still pretty unwieldy, but at least grammatical:
The question of how far / the extent to which
(we/they/XYZ?) (will) succeed in developing transparent, comparable, and significant standards
will determine whether the intellectual capital report
will one day / eventually
replace the present financial balance sheet,
supplement it as an independent report,
or remain purely a market instrument.
Or the last part in simple present, though I don't like that quite as well:
... will determine whether the intellectual capital report one day / eventually
replaces the present financial balance sheet,
supplements it as an independent report,
or remains purely a market instrument.
Or if you really don't have a person or organization to answer the question of 'gelingen wem,' then the passive may be the lesser evil:
The question of how successfully ... standards can be developed will determine whether ...
Better still, of course, might be to break this monster into two parts, e.g.,
XYZ is currently seeking / planning to develop / has been given the task of developing (/ etc.) transparent, comparable, and significant standards for [blablabla].
(The question of) The extent to which they succeed will determine whether ...