In SharePoint 2010, sites can export custom list items to Excel using the Export to Excel option in the ribbon toolbar. It will export all items in that particular view in which the option is invoked. SharePoint literally is not exporting the items it creates in the query file instead, which will have the view id and helps to query the SharePoint list data and the results are shown in the excel spreadsheet.
Now if you need to export only specific items from the list. Let's say if you want to export only 10 items out of 30 items shown in the view then there is no direct option for that. Then you need to create a view and apply filter to extract only the specific 10 items which you want to export and then you have to export. But you can' t create views every time to export any specific items.
To overcome this situation, Try using the below WSP,
SharePoint 2010 - Selected items export to excel.