Help with Permalinks / URL Re-Writing on IIS7

Hi,
I’m moving my existing old blog over to WordPress and would like to ensure I don’t lose traffic to old URLS.

My existing URL structure is:

Homepage: sitename.co.uk/index.asp
Category: sitename.co.uk/category/index.asp
Pages / Posts: sitename.co.uk/category/postname.asp

I have set wordpress up as follows:

Homepage: sitename.co.uk/
Category: sitename.co.uk/category/
Pages / Posts: sitename.co.uk/category/postname.asp

with the following code in the web.config file:

<rule name="wordpress" patternSyntax="Wildcard">
					<match url="*"/>
						<conditions>
							<add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true"/>
							<add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true"/>
						</conditions>
					<action type="Rewrite" url="index.php"/>
				</rule>

and that works fine.

My question is, using the web.config file how do I redirect

Category: sitename.co.uk/category/index.asp to Category: sitename.co.uk/category/ – i.e lose the /index.asp on the end.

I have a ton of backlinks to the /index.asp pages and really would like to do a re-write rather than lose all of this.

Thanks