In an InputScript I have a variable V[Z_abs] with a value between 1 and 99. What is the best way to ensure the inclusion of a leading zero in the statement (e.g.)

Enter "=SX06" 

if  the value of the variable is "6", for example?

You can use

if V[Z_abs<10)
  Enter "=SX0&V[Z_abs]"
  Enter "=SX&V[Z_abs]"