Browse Dialog Box in a webpart

[AsWaM007]

I want to add a "file selector" that allows the user to select a (xls) file and returns me the full path of the file (e.g. C:\MyFolder\MyFile.xls) for further processing

I wanted to use the System.Windows.Forms.OpenFileDialog , but sharepoint does not want to open it (I can compile, deploy but when I press the button, i have an error)

Thanks

I want to use it to import content from an Excel File, i must retieve the file path (my problem) the convert it to XML, test if it fits my schema, and then if it does put the content in a list.