The IdcDbg plugin for IDA Pro is/was an attempt to wrap debugger functions of the IDA Pro sdk in IDC language. The goal was to be able to write small IDC scripts which can find the original entrypoint of packed executables, circumvent complex anti-debugging tricks and dump the executable image in memory. Unfortunately, the IDA debugger seems to be badly implemented. At the moment the user cannot even read/write register values correctly using IDC, which makes the plugin worthless for above mentioned purposes. I hope the IDA debugger will have a general overhaul, soon ;-)
