>It may be not a full solution, but you can use an API fuction
>"PathIsURL" (available under Win98/2000 or IE 4.0 installed) to
>determine if string conforms to a valid URL format:
>
>Declare Integer PathIsURL in shlwapi String @ pszPath
>?PathIsURL('http:\\www.microsoft.com')

I need something generic returned by the function as this is also needed to check for a mailto.