It is not clear from your question exactly what you want to do. It sounds like, since you don't want to copy a image (gif file) to Excel that what you want is to copy the data that is in the chart into an Excel spreadsheet.
One way of transferring data from a C# program to Excel is to save the data to a CSV file. A CSV file (Comma-Separated Values) can be opened by Excel.
At
this link[
^] are some basic examples of exporting data to a CSV file.
You don't specify which version of Excel you are working with, but if it is from Office 2007 or later you can use the
Open XML SDK[
^]. CodeProject even has
an article[
^] about how to use this SDK.
If you want your code to create an actual chart in Excel that is also possible. Take a look at
this link[
^] to get started.
After you have written some code to transfer the data and you get stuck feel free to ask questions here. Include the code you have written so far as well as a detailed description of any error messages.