Noncentral bell curve distribution random number generation in PHP

I'm looking to create a function that can create a random integer based on the Noncentral t-ds (http://ift.tt/1NCdzza). I have been playing around with the PHP function:

stats_rand_gen_noncentral_t() (http://ift.tt/1Jcbq83)

This seems like it should do the trick, although I'm struggling to find out what parameters it takes. Only two? There's very little documentation for it out there.

I'm looking to be able to pass a min and max value to a bell, and to set the 'most likely' value too- ie. the tip of the bell.

For example, I'd like a result set where the likeliest of results is 80, the minimum possible result is 5 and the maximum result is 120. Is there a different way to approach this that I haven't considered?