Shell Programming and Scripting

we want to produce a script that we can pass parameters of -a for email address and -s for subject then the report filename, so an exmaple would be;
email_report -a sendto@domain.com -s This is a test reportname.txt

The problem we have is the subject can have more than one word, so I can't just get the next para after the -s. What I need to do is maybe place the subject in quotes so I can extract from the starting to the ending quote?
Then how do I get the filename, as it 's the last parameter?

Write the script so that the report is standard input, then the command would be:
email-report -a mail@address -s "This is your report" <report filename
If the report is the entire body of the email, then:
mail -s "this is your report" mail@address <report-filename

I got around this by formatting the script as;
email_report -a email@address <reportname> -s "subject goes in here"

so I grab the -a param
the next parm is the report name
the rest is the subject