It sounds as if you will have to enter the terrifying
realm of Format/Bullets and Numbering. If you are trying
to number the paragraphs manually you have already created
a living hell for yourself. Word doesn't like freedom.
To acquire lower case numbering you will have to tell the
Bullets & Numbering god just how you want it, and then be
sure it's saved to your Normal.dot template when you exit
WORD.
Pull down Format, then click on Bullets & Numbering. You
will see choices of bullets, numbering or outline. If all
you want is simple one-level numbering, use "numbering"
and choose the lower case alphabetical style. It places
the letter one tab from the margin. If you need it AT the
margin, you can move the little gray dealies on the ruler
(if you have the ruler showing). They govern where the
first and second lines hit on the page.