Database deployment issues

Question

I'm developing a little app that will be deployed as a .dll file so that anyone can add it to their application build as an "add-on" fetaure.  My app uses a sqlserverce .sdf file for storing very some user information.  Since this .dll will or could be placed virtually anywhere on some end user's PC, is there a way to setup a connection string to my data.sdf file so no matter where they install their program, it can still be accessed by my .dll file?  I'm sure it needs to be in the same folder, but how do I script maybe a current directory?

Thanks,

kevin