Item rule set expression assign to org

Good morning guys.

I need to create an automatic item assignment rule with the following condition.

if item_number startswith 'CT' then

assginedToOrg 'A','B','C''

else

assginedToOrg 'E','X','Z''

end if

Would it be possible to create a rule with the above conditions?

I did some tests and I couldn't create the rule.

Has anyone managed to create rules this way?

Tks