Hello,i am an beginner.
i wonder how a softcam works,
can i use it on a toppfield 3000co-ci
please help. poj in sweden.

You probably mean SoftCam.key. It´s a file that contains all (or almost all)the available keys of encrypted programs. It´s made for Dreambox and is needed for mgcamd emulator (mgcamd reads the keys from SoftCam.key).
You can use SoftCam.key file for all receivers or cams where the keys can be entered manually (with the remote) if you open it and take out the relevant key. It can be opened with note pad or word pad.