Scripting: Using Variables and Math in CCs

I am working on a series of buttons. One type of button is a toggle that will turn on and off with specific values. To make changing the values easier for each button, I would like to use variables. I get an error about the channel needing to be between 1-16 with this script.

I know I am doing something incorrectly here. Would anyone be able to point me in the right direction?

Thanks, - J

Code:

[(init){@local_bu:3} {@local_ch:1} {@local_co:1}]
[(press){cc:#@local_ch#,#@local_co#,#@local_bu#}]
[(release){state:1}]
[(press){cc:#@local_ch#,#@local_co#,#@local_bu+64#}]
[(release){state:0}]
[(cc:#@local_ch#,#@local_co#,#@local_bu#){state:1}{nextpress:2}]
[(cc:#@local_ch#,#@local_co#,#@local_bu+64#){state:0}{nextpress:1}]