Can I get Excel to open up a new workbook based on a particular template from an html page? I can open the template directly but this then assumes that you're wanting to save as a template. It's internal use only so needs only deal with Office 2007 & IE8.
To clarify: you're wanting to make a .XLT (or .XLTX or .XLTM) file available on a web page, and have it used as a template?
Interestingly, when I try this with Excel 2007 and Chrome, it works fine. With IE8, I see what you describe.
Do the templates have to be on a web page? Can you put them on a UNC and configure Excel to look there for templates? Note that, bizarrely, the template location affects the whole of Office and must be configured in Word's options dialog.
I was hoping that I could point Office at the templates location using WebDAV, but no dice in the few minutes I spent on it.