Get/Set path for ApplicationPoolIdentity?

Question

I have a WCF-service who uses a dll placed in the GAC. This dll uses another native dll. The native dll is by default placed in a installation folder under c:\program files\bla bla.. After installting my service in IIS 7.5 it wont run. I get an error saying that my the managed dll dont find the native dll. If I move the native dll to SystemWOW64 the managed dll finds it and everything works as expected. I want to try if I can change the path instead of moving the files. The service is using the DefaultAppPool and the default account ApplicationPoolIdentity.

My questions are, is there any way to see the path for ApplicationPoolIdentity? Can I set the path for ApplicationPoolIdentity?

Thanks!