How to get 'bitmap' from 'ISymbol'?

Discussion created by aviabunin on Jul 5, 2011
The problem is to customize symbol, by adding the text on it.
I get symbol as follows

And now it is desirable to get bitmap from that symbol to draw the text on it
System.Drawing.Bitmap dotNetBmp   = 

and make symbol as follows:
ESRI.ArcGIS.Display.IPictureMarkerSymbol bitmapPictureMarkerSymbolCls.picture = ESRI.ArcGIS.ADF.COMSupport.OLE.GetIPictureDispFromBitmap(dotNetBmp)
                                                 as stdole.IPictureDisp;

But I can't to get bitmap from symbol. Can anybody help ?
Thanks for any advise!
P.S. The added text is the value of some properties of the shape, wich signed by this symbol (the number of poligon).
Is it possible to modify symbol on the fly, when drawing on the display?