Default Widgets in new theme

Hi All

Im after some code and its either really easy and I cannot find it anywhere, or its really hard and cant be done! So Im after some help/advice/pointers if possible.

Im rebuilding one of my themes for WordPress and wish to have some of my own plugins pre installed- so they will be in the theme folder and by default loaded into the relevant widget areas by default.

I can get the widgets to work, appear in the widget selections etc, but for the life of me I cant get how to add them to a widget area by default by calling the widget name.

Could someone point me in the direction of any good tutorials or even just put me out of my misery and tell me it cant be done! Thanks!