[Typo3] Converting existing site to TYPO3

[James Walsh]

Firstly many thanks to Luc & Bart for earlier good advice on TYPO3 and SEO.

I need to convert an existing large site (250 HTML pages) into TYPO3. Currently the pages
produce standard HTML via php scripts which insert dynamic headers, footers and sidebars.
The pages are well established in Google and Yahoo and I don't want to lose these rankings
when I convert to TYPO3. My specific questions are :

1) Is there a tool or process that will easily automate the conversion of an existing site in this format to TYPO3 ?

2) I need to keep exactly the existing directory structure and particularly page names as they are indexed
    already by the search engines. How ?

3) The existing pages use PHP to dynamically generate specific html headers, sidebars, footers
    per page. It seems that it is possible to use TYPOScript to call the same php scripts for
    headers and footers. I've searched through the examples in the documentation, but can't
    find an example of this ? Any examples would be much appreciated.

Note : I am using a normal hosted account on a Windows server, and so I don't have Linux/Unix
or command line access.

Thanks in advance.