Hi Georgi Kashev,
My apologies for addressing to the wrong person, it was meant for you.
You can extend GridStyleInfo to hold your own custom properties. For example, the style.MaskEdit, style.CurrencyEdit and style.FormulaTag are extended properties added to the GridStyleInfo class. So, if you have the grid source code, you could take one of these (the FormulaTag may be closest to what you have), and create your own extended style property mimicing that code.
Here is a link to a sample showing this process which might be simpler.
CustomstyleInfoSample.zip
also refer the Browse samples:
syncfusion\essential
studio\3.3.0.1\Windows\Grid.Windows\samples\CellTypes\PictureBoxCells
syncfusion\essential
studio\3.3.0.1\Windows\Grid.Windows\samples\CellTypes\SliderCells
Let me know if you need any further assitance.
Regards,
Haneef