Change the value of tag through transaction

Hello,

I want to change the default value of the tags which are present in the simulator services through the transaction. I want to change the value to expression and not integer value.
Current value of tag is 96-(rand()*12)

and i want to change it to some other expression for example 91-(rand()*19). I tried to add this expression in the tagvalue.1 in links of the tagquery action but it giving me "invalid data values" error. Does anyone knows how to do this?

Message was edited by: Michael Appleby