setting apache directive in directive snippet

How can I set this directive in directive snippet:

Code:

# 480 weeks
<filesMatch ".(ico|pdf|flv|jpg|jpeg|png|gif|js|css|swf)$">
Header set Cache-Control "max-age=290304000, public"
</filesMatch>

When I am inserting above directive, it is being stripped and is shown like this

Code:

# 480 weeks

Header set Cache-Control "max-age=290304000, public"