How to run multiple projects from testrunner.bat

I have multiple projects under a work space.
I would like to run all projects from a console by testrunner.

For example, if I issue this command from the console, the test runner doesn't run the test:

"testrunner.bat -a -fD:/myResultFile  D:/soapUIProj/myProj_1-soapui-project.xml D:/soapUIProj/myProj_2-soapui-project.xml -j -o -r"

But if I issue only one project, then everything is fine.