The file (fetching and) processing takes place on a Solaris box; I'm not aware of any way of running VB script without using a Windows OS.

As a total aside, I am beginning to dislike this problem, as it looks like I'm going to have to use SOAP to fetch the file now (and in some awful flat WSDL format) which is causing completely different problems - but I am betting that other clients will wish to supply (non binary-xml) Excel, so the current parsing solutuion is of use. Look out for my next question in SoPW!