Project.Variables.<insert variable> is referencing the currently running project, I don't think there is way for it to reference another projects variable. Are you sure the variable just isn't getting set properly? Try logging the variable when it changes to make sure that's it's actually changing to what you expect it to.
Thanks for the reply on this, apologies for not getting back sooner, just back from holiday...
Looks like this was a mistake on my part as I was setting the NameMappingStr project variable to the wrong value. I spotted it straight away after my holiday....amazing what a difference fresh eyes can make!
Once again, thanks for replying cunderw!
