[R] probability plot correlation coefficient

[anne]

As a newbie to R, I'm still rather at a loss for finding information 
(the commands names can be rather arcane)so I'm just posting my question:
I would like to estimate   the shape coefficient of diverse 
distributions (Weibull, gamma and Tukey-Lambda specifically, but other 
could be of interest)
- Does R have a PPCC utility to estimate such parameter?(maximum value 
of correlation coef)
- If yes how does one retrieve the numerical value from the graph? (see 
graphical example below)
- The retrieval of numerical values is also a problem for me from the 
probability plots....




Thank for any help!
Anne