I'm trying to use Web Deploy 3.0 to make changes to my web.config before deployment. Let's say I have the following xml:

```
<node>
    <subnode>
        <connectInfo httpURL="http://LookImAUrl.com" />
    </subnode>
<node>

```

And I'd like to match just the "http" in "http://..." so that I can potentially replace it with https.

I looked into XPath string functions and understand them -- I just don't know how to put them in the middle of an expression, for example:

```
"//node/subnode/connectInfo/@httpURL/substring-before(../@httpURL,':')" 

```

That's basically what I want to do, but it doesn't look right.