Microsoft Excel Chart

I asked 5 times about this question and I'm not resolve my problem. Who can help me?

I put object Microsoft Excel Chart in my form and the chart was build with sheet1 situate in the object Chart1 but I will like to change data on sheet1 to make a new chart but I not able.

I try with Worksheet("Sheet1").cells(2, 3).value = new value but I receive all the time this error "Method or data member not found" for Worksheets.

I think my problem as to select the sheet in the object? But am not sure. I will like to take data in DBGrid and put them in Sheet1.

Help me !

Sorry for my english
Thanks
Redg