How can I create a cashflow stream that will insert capital costs and revenue streams at specified dates

[Josh Mathews]

I want to create a module that will easily allow me to quickly run sensitivities onthe NPV of a project by varying capital costs and capital deployment dates, as well as revenue start dates. I set up text boxes for "project as of date", "capital expenditure 1 amount", "capital expenditure 1 date","capital expenditure 2amount", "capital expenditure 2date",.... all as property controls.The same is true for Revenue streams. How can I create a stream of cashflows that uses those inputs and will change the stream according to the expenditure amounts and dates I enter