They tend to use pretty standard regular expressions, so if you search for a regex cheat sheet, you should find a good example. I use one from AddedBytes.com. That being said, regex's can be tricky... For the simple string find, I do believe that "*" matches any number of anything, while "?" matches one of something. Only count on using the "*" once in any given line.
That being said, I choose to use a regex for matching our banner, worked out best that way. My regex converted to your use case above, would look something like this (I'm counting on # not being a meta character that needs to be escaped, I don't believe it is).
banner motd\s*\^C
#+ COMPANY #+
\s*
Unauthorized users will be prosecuted to the fullest
extent of the law.
\s*
Contact network@company.comor call \(555\) 555-1212 to
report trouble associated with this equipment.
\s*
#+ COMPANY #+
\^C
Brief explanation, ^, ( and ) are a meta-character that needs to be escaped with a \. '\s*' just says any number of spaces can be here (even none). #+ just says there should be one or more '#''s there. Hope this works, might need some tweaking. I did get mine working with something similar