Hi Oleg,
my scripting isn't that good and I have not been able to make what you suggest work.  
This is what I have at the moment in vbscript.  I get a WScript object and call run.  When I do this I have to pass in the php.exe path and the file that php is going to act on.  After that it ignores any output redirection.
'	run generator, don't show cmd shell, wait for cmd to finish before continuing script
	oWShell.Run """C:\Program Files (x86)\PHP\v5.3\php.exe"" ""D:\ThirdPartyWebsites\XmlSitemapGenerator\runcrawl.php""" , 0, true
I have tried variations of this but I can't get it to work.  That is moving where the "> output.log" part goes.
'	run generator, don't show cmd shell, wait for cmd to finish before continuing script
oWShell.Run """C:\Program Files (x86)\PHP\v5.3\php.exe"" ""D:\ThirdPartyWebsites\XmlSitemapGenerator\runcrawl.php"" > output.log" , 0, true
Any other suggestions?