Milind,
thanks for your comment.
Since I do not know the structure of your workbook, I will refer to the cell ranges of the workbook posted for download in the article (the advanced version):
The VBA which is called when you enter something in the textbox changes 2 cells on the worksheet control: cell C4 (mySearchPosition) and cell C6 (mySearchString). You have to make sure that both cells are unlocked (Format Cells|Protection|Uncheck Locked).
I hope this will be helpful.