Creating a workflow rule to assign category

[chrish]

Hi all, I am trying to create a workflow rule that assigns ticket categories based on the subject line from automated emails. There are different subject lines based on the process and the country and location (the emails are triggered from SuccessFactors). For example, it could be Your attention is needed on a workflow Inv - Performance USA - 277 or Your attention is needed on a workflow Vol - Personal / Family USA - Y31. I need a way to assign the category based on the start of the email (e.g. Your attention is needed on a workflow Inv - Performance), but the options I see need the full subject line. I have multiple processes, multiple countries and over 100 building codes so it is not practical to set up a rule down to this detail. Does anyone have any suggestions? Many thanks!