You can use the macro snippet in an Outlook VBA procedure to create a new message and load your HTML into it:

Sub MakeHTMLMsg()
Set objMsg = Application.CreateItem(olMailItem)
Set fso = CreateObject("Scripting.FileSystemObject")
Set ts = fso.OpenTextFile("c:\testfile.htm", 1)
strText = ts.ReadAll
objMsg.HTMLBody = strText
objMsg.Display
Set fso = Nothing
Set ts = Nothing
Set objMsg = Nothing
End Sub

Once you have the message displayed you can use the Save As command to save it as an .oft file.

Note, however, that your HTML may or may not be suitable for an email message. You should to test it thoroughly with a variety of receiving email applications.

Sue Mosher, Outlook MVP
Author of Microsoft Outlook 2007 Programming:
Jumpstart for Power Users and Administrators
http://www.outlookcode.com/article.aspx?id=54

"Mark" <mark_weyman@hotmail.com> wrote in message news:CB924E9C-FABA-4AA9-9C03-99EBA92AD2BE@microsoft.com...
>I have a newsletter template that I have created in an HTML authoring tool
> (outside of Outlook 2007).
>
> I now want to use the content as an Outlook template and want to know the
> best way of converting the content into an Outlook .OFT format. I have tried
> to cut/paste with no luck and can not work out how to access the code view
> of the object.
>
> - Puzzled!
>
17 Mar 2008Convert HTML into OFT format?.Mark
17 Mar 2008\ Re: Convert HTML into OFT format?.Sue Mosher [MVP-Outlook]