R or S-Plus regression code Help?

hey i have a few questions for anybody who knows their code in either r or s-plus, that can help me out

1) I need to find a 99% confidence interval for the mean burglary rate of a city, with population of 70.

i tried to use this formula

*pop70 = predict(model1,as.data.frame(popdens),se.fit=T, pi.fit=T, ci.fit=T)*

but it only provides an answer with a default setting of CI of 95%. does anyone know how i could get the answer with 99% CI?

2) How do you fit a regression through (0,0) (origin), and how do i test if there is a significant regression at say alpha = 0.05 at origin?

3) How to illustrate a barplot of leverages, and impose a flat line at height 3/n?

thx in advance :)