The RequestParameterModule can be used for matching multiple request prarameters.
The WEB-INF/cocoon.xconf file entry should look like:
<input-modules> ... <component-instance class="org.apache.cocoon.components.modules.input.RequestParameterModule" logger="core.modules.input" name="request-param"/> ... </input-modules>
Then, in your sitemap, you can use {request-param:foo} or {request-param:bar} to get the values for parameters foo and bar.
<map:match pattern="test.pdf">
<map:generate
type="file"
src="cocoon:/test.xml?foo={request-param:foo}&bar={request-param:bar}"/>
<map:transform .../>
<map:serialize .../>
</map:match>