My own add feature function

Hello,

I have defined, in Geospatial  Administrator, a linestring feature. But I want to create/draw it in a special way. I have written my own MDL command supporting drawing orthogonal buildings process. And now I'd like to combine standard feature creating tool with this command. In other words, the result I need is to have a command that creates a feature drawn using my MDL function. Where should I call this command?

Myzzard