Replacing part of a cell text

Hi there!

I'm working on a macro to automate my project, One thing i need to do now is to replace the numerals in a cell from another cell. For example, in sheet1 C2, i have this numeral 20. I will like this macro to replace sheet3 C2 which contains data such as 11. I want the numeral 11 to be replaced by 20. Hope someone can help with this!

Another thing is how do i call from excel macro to ask notepad to open up a .xml file? -- solved this part!

Thanks a lot!