Can you clarify what you want to accomplish?
The "Say Something with Text-To-Speech" action supports any token, and tokens can retrieve variables.
Also note that dynamic sections are processed last, so something like
Set Text [SayText] to 'Option [one;two]'
Say, 'I'll take {TXT:SayText}'
Will use the value from the variable, and randomly pick between the bracketed sections, as it normally would.
However, the randomization is done in the action itself, the variable itself always contains the full text.
If you want randomized text outside of the TTS action, you can use the "{TXTRANDOM:}" token(VoiceAttackHelp.pdf page 105).