To be able to insert translated labels and messages for workflows you have to enable the multi-language option for the following attributes:
To set multi-language option go to System Configuration > Platform Configuration > Database Configuration find each attribute and set the 'Multilanguage in use?' flag. Enable the admin-mode and apply database changes.
After having done this you should be able to login as MAXADMIN with a different language and set different labels for actions and tasks using the standard 'Workflow Designer'.
Reference IBM TechNote: Setting up Multilanguage for Workflow