How do I use logical OR with strings?

Compare Two Values:

left(Controls.Get(ControlMenuObject.Type),3) = (MouseString_LMB | MouseString_MMB | MouseString_RMB)

equal to

TRUE(1)
[/code:19gpt8wm]

Basically, I'm trying to see if a given string matches 1 of 3 values(global string vars). So, put more simply:

[code:19gpt8wm]string foo = "foobar"

Compare Two Values: 

foo = ("foo" | "foobar" | "foobert")

equal to

TRUE
[/code:19gpt8wm]

Compare two values:

foo = "foobar" | foo = "footaro" | foo = "fooji"

equal to

1(True)[/code:qddidw3o]