Most programs that offer an icon near the clock have a setting to enable or disable it. Sometimes they add an entry to the Sytstem Preferences pane on the bottome row, so check there and look at every tab carefully for a checkbox to remove the icon.
If you deleted the program, you might need to reinstall it and check all the options in the program to find the option to remove that entry--then see if it has an uninstall feature.
You also might want to check the "Accounts" settings in the System Preferences pane, then look under "Startup Items" to see if that program is loading on startup (perhaps from another folder other than the one that you deleted).
You can also check /Library/StartupItems (that is the Library folder from the root, not the one under your user ID). If you see something with the name of that program, you might want to read the entries, find the source program, then delete everything.