Find the 'Export' button on the top right corner of the HelpDesk issues list:
Click on it to download the .csv file of the selected tab in HelpDesk. The column values shown in the current tab will be exported.
Import the .csv file to Excel file (File → Import) selecting the UTF-8 as the file origin, select semicolon as a delimiter.
Jira Administrator may set up the list of columns to be displayed for each tab in the User Dashboard settings.
HelpDesk administrator can set the export encoding from HelpDesk issues list.
To do set up Export encoding
Go to HelpDesk administrator menu > Access;
Select the export encoding