First some clarifications: It depends on Office, yes, but it doesn't matter if it is 2007 or 2010. It works with both versions.
Now to your question:
I would create a new ribbon button like this:
Create a new feature.xml and a new elements.xml. Paste the following code in the elements.xml:
<?xml version="1.0" encoding="utf-8"?>
<Elements xmlns="http://schemas.microsoft.com/sharepoint/">
<CustomAction Id="OpenExplorerButtonNew" Title="Open in Explorer"
RegistrationType="List" RegistrationId="101"
Location="CommandUI.Ribbon" >
<CommandUIExtension>
<CommandUIDefinitions>
<CommandUIDefinition
Location="Ribbon.Library.Actions.Controls._children">
<Button Id="Ribbon.Library.Actions.OpenExplorerButtonNew"
Command="OpenExplorerButtonNewCommand"
LabelText="Open in Explorer"
Image32by32="/_layouts/IMAGES/ctoc32.png"
TemplateAlias="o1"
/>
</CommandUIDefinition>
</CommandUIDefinitions>
<CommandUIHandlers>
<CommandUIHandler
Command="OpenExplorerButtonNewCommand"
CommandAction="javascript:
var currentUrl = window.location.href;
var modifiedUrl = currentUrl.replace("/", "\\").replace("http:", "").replace("https:", "");
window.open(modifiedUrl);
"/>
</CommandUIHandlers>
</CommandUIExtension>
This will create a new button in the ribbon and on click it executes the specified javascript.
Within the javascript get the current url and replace the characters as you mentioned. Then try to open the modified URL. That last one is the part where I'm not sure whether that will work.