Drop caps or Big first letters have been discussed in various places here at MR. (hint: Search. Also note they tend to be
dissed as not all devices support and can cause 'returns' in the marketplace)
The CSS code snippet is not huge, and can be
tuned to conditions.
Depending on where in the
Page you want to use one, the REGEX to
wrap the character(s) in a Dropcap Span can be quite simple.
eg drop wanted on the first Paragraph after the Chapter head
Code:
(</h3>\s+<p class=fp">)([A-Z]}
\1 <span class="dropcap">\2</span>
(there is more REGEX elegant code to get it done, but this works

)

remember to handle leading quote character you use