offGCD command in a conditional?

I would like to be able to do something like:

/cast [mod] offGCD spell, spell1; spell2

Is this possible?

Not sure which of these you’re after

/cast offgcd
/castsequence spell1, spell2
#showtooltip [mod] spell1; spell2
/cast [mod] offgcd
/cast [mod] spell1; spell2

If you can provide a specific example so can we.

tooltip is not important. what i am looking for is to cast the offgcd with only spell1, due to the different cooldowns of the spells.

You want the 2nd version.