In order to create a launcher for a particular OpenOffice application, or if you wish to run one from a terminal in Linux, you will need to know which command opens each application. Unlike Microsoft Office, for example, there is one command to run OpenOffice to which you can add a parameter to run a particular application.
Command to run the Writer word processor: openoffice.org -writer
Command to run the Calc spreadsheet application: openoffice.org -calc
Command to run the Impress presentation application: openoffice.org -impress
Command to run the Base database application: openoffice.org -base
Command to run the Draw vector graphics editor: openoffice.org -draw