Is this some sort of performance testing software, I can't think up many situations where software would restrict the use of a normal mapped network drive.
I have found a program that might do what you are looking for though.
Perhaps you could setup an ISCSI device on your network storage device ?
This seems to be supported by windows 7 and would allow a more natural solution.
Fair warning there is something to be said about fooling windows into thinking you have a local drive that is on the network and it starts treating it like one you might cause some inherent serious slowdowns on your overall PCs performance if not setup well ( I cannot vouch for any of the software ).
Some very old issues on server fault go into this for example:
Please let me know if it helps you.