This might not help the OP, but to future SAS programmers who are searching for the Poisson-binomial distribution in SAS, I have written a few articles about it, based on the paper that the OP posted:
An introduction to the Poisson-binomial distribution
Density, CDF, and quantiles for the Poisson-binomial distribution (exact method)
The Poisson-binomial distribution for hundreds of parameters (approximate method)
All the articles use PROC IML. As @SteveDenham mentions, the RNA (discussed in the third article) is your best bet for an approximation in Base SAS. You can use PROC MEANS to get the mean, std dev, and skewness of the parameters, save those values in macro variables, and then use a DATA step to compute the CDF and PDF.
How to get the quantile function in Base SAS is less clear. Maybe the simplest (and easiest) way is to throw out the paper and use Monte Carlo: Simulate 100,000 observations from the P-b distrib and use the empirical quantiles.
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