I'm not quite sure of what you're intending happening here - as, each computer you've registered on WCG, will have (or as far as I'm aware, should have), a unique 'Device Name', under your one generic 'Member Name'.

If you decide that you want each computer to have it's own 'Member Name', then all the points/time credited (for badges etc) accumulated by each individual computer, will be assigned to that particular 'Member Name'. Doing it this way, will also mean having four separate Member Name/Password combinations to remember. Currently (and this will probably stay this way for a very long time - i.e., more likely, for ever), there isn't a way to "merge" Member accounts, and thus, each of your computers contribution will remain separate for ever.

If you're wanting to specify which projects are crunched on specific computers, this can be done already from within your Device Profiles settings (home, work, school etc.), where certain devices can be aligned to certain profiles.