301 Redirect with dynamic url

Hi,

We are trying to accept old inbound links, that are currently bouncing.

The old urls contain: /County_Detail.cfm/CountyID:XXX   (XXX = UniqueID)

We want the old links to redirect to /Counties/County_Detail.cfm?CountyID=XXX

We're using CF10 and IIS 8.5

We simply want to replace the delimiters / and :

We've tried a number of settings, with the following as the latest. 

Would someone kindly point out the error of our ways.

<rewrite>
<rules>
<rule name="Rewrite Counties" stopProcessing="true">
<match url="^County_Detail.cfm([a-zA-Z0-9-+]+)CountyID([a-zA-Z0-9-+]+)" />
<action type="Redirect" url="County_Detail.cfm{R:1}CountyID{R:2}" />
</rule>
</rules>
</rewrite>

Thank you, so much!