Thanks for all the help folks.

I just ended up creating an extra little subroutine "Sub
RunRemotely()" in the excel file which gives the specified values to
the two variables - the vbs file now just looks like:

Set XL=CreateObject("Excel.Application")
XL.Visible=True
XL.Workbooks.Open "\\imsfileserve\xxx.xlsm"
XL.Run "'xxx.xlsm'!RunRemotely"
XL.Workbooks("xxx.xlsm").close false
XL.quit
Set XL=nothing


....ONE FURTHER QUESTION:
I'm using these .vbs files, run using Scheduled Tasks, to run various
macros on a server dedicated to churning out Excel reports - what
alternative methods would you use? (bearing in mind the routines can
take upwards of 20minutes to run using lots of aPCs resources while
running ?

All help appreciated
Jason.