Ok then. A decision to do specific work doesn't absolve the OC from its responsibility under section 62 to carry out any other works that may be necessary, so whomever is telling you that this has to be done first is not correct (based on the information given).
A special resolution doesn't give something special priority, it just means that the resolution needs a particular level of vote. Of course, there may be all sorts of permutations – for example the specific work may be necessary before other work can be carried out although it doesn't sound like that is the case here. Also – it may have been decided as part of the special resolution to raise a special levy that relates to the works, but that is unlikely as a special levy doesn't require a special resolution. The special resolution was likely to relate to the exclusive use.
As noted above the OC still has responsibility to carry out any other necessary works and should have money in its sinking fund to do those. If not, it will have to raise more money. I would go back to whoever has told you this and remind them of the OC's obligations under section 62 and ask them why they are not being met. There are cases on this including a woman who went to the CTTT to get an antenna fixed because the OC told her other works had priority. She got the antenna fixed.