I would like to fit a distribution e.g gamma/weibull to a data set to produce a cdf, where I force it through a select value at a given percentile. How can I go about doing this?

I know I can use the fitdist function to fit a gamma or weibull distribution to may data, but I was wondering if it was possible to adjust this to force that fitted distribution through an exact point? Thanks!

Let's look at an example with a Normal curve:

x <- seq(-4,4, length=200)
y <- dnorm(x, 0, 1)
plot(x,y, type="l", lwd=2, col="red", xlim=c(-3.5, 3.5))
points(2, .2, col="black")

You could shift the curve up, or you could shift the curve to the right. Is that what you want?