changing section heading indentation

[shawn fitzgibbons]

I need some help with margins for paragraph and sections. I need the 
section headings to be 3pc from the left margin, and the paragraph 6pc 
from the left margin (not the first line indent, but the whole 
paragraph). One way to do this in latex is to set the page margin at 
6pc, and then for each section, specify {-3pc}, but adding this to the 
lyx document appears to have no effect. Is there a global setting that I 
can make in the preamble to make all headings {-3pc} into the left margin?