thank you for your good solution but your solution always assume external workbook to be open, how to work with current opened workbook?

Dim oxcel As Excel.Application
Dim owb As Excel.Workbook
Dim osht As Excel.Worksheet

oxcel= New Excel.Application
oxcel.Visible = True
owb= oxcel.Workbooks.Open(Path)
osht= owb.Worksheets(1)

now I developing add-in and I want when user click on special button in new ribbon then he get results in the workbook he working on it, not to open new workbbookbut until now I can't find solution.
please help me to work with activeworkbook.
thank you

Please help me, really i should finish this in short time.
I need help.