pyscripter/XLRisk

AI Summary: Implement a Poisson distribution function within the XLRisk Excel add-in, mirroring the functionality of the RiskPoisson function in Palisade's @RISK software. This involves adding a new function to the add-in's VBA code that accurately calculates Poisson probabilities based on a given lambda (average rate of occurrences). The implementation should adhere to the specifications outlined in the provided @RISK documentation.