Storing Custom Form in Layouts instead of Features

How can I deploy my custom form to the layouts folder instead of features?

I followed several guides on creating custom forms which is deployed to the features folder and the they work! However, I would need to know how to define my SetupPath value so that I can deploy it to the layouts folders.

<Form Type="NewForm" Url="NewForm.aspx" SetupPath="features\$SharePoint.Feature.DeploymentPath$\AssetDetails\Forms\AssetNewForm.aspx"  WebPartZoneID="Main" />