All,

Problem solved. Here is an example of the correct format  : 

XCOPY /Y "F:Poser Runtime/Textures/RMKyonRMKI2.jpg" "C:Program Files/e frontier/Other Runtimes/Miki/runtime/Textures/RMKyon/"

I found out that XCOPY needs to know whether you are copying the file to another file or to a directory. To avoid any such ambiguity, you simply place the / character at the end of the destination's directory path, and leave out the destination file name.

The quotes are to cater for spaces that are embedded in the directory path. The /Y switch is to suppress any confirmation prompts - which is good news for batch files.

Thanks one and all for your help.

regards,
Andrew