Hi,
when you write
import Qt 4.7 or
import myPlugin 1.0
QtCreator goes to the "qt/imports" directory and looks for a folder named "myPlugin". You should place your plugin.dll inside the folder you created with myPlugin name.
1. Create a folder whose name is myPlugin under the "qt/imports" directory.
2. Give that path in the pro file with DESTDIR = ../qt/imports/myPlugin
whenever you compile your program, it will create the dll inside that folder.
Hope it helps