Also, how long is your investment horizon? Is it really that important to you to project out to 30 years or is 3λ years sufficient along with a terminal value that represents the expected NPV beyond 5 years? Usually this latter approach works best and looks the most credible to potential investors. There are numerous ways to calculate terminal value including multiples, current market values projected forward, and round guesstimates. Obviously these decisions are affected by your personal preference and the type of investment for which you're calculating present value.
Next, how much detail do you need in your cash flow template Excel spreadsheet at the individual line item level? Is cash from financing sufficient or do you need equity financing, debt financing, interest earned, etc. Also how do you intend to handle depreciation and amortization, since these are non_cash items that are typically added back to the income statement entries when determining the cash effect.