looking for nicer way to have variable in the middle of string

i want to create a string where the variable part is in the middle, iRule / TCL doesn't totally get this.

 

 

the line below causes the system to assume the variable is $variable_fixedpart2, not just $variable

 

 

set name "fixedpart1_$variable_fixedpart2"

 

 

this works:

 

 

set name "fixedpart1_$variable"

 

append name "_fixedpart2"

 

 

but is there a nicer way, in one line for example?