You can put the text into a numeric variable using the string variable contents. You could then use a conditional "if" to check the numeric value was in the correct range.
So the commands might be:
[list]
[*]Print -> Print a message: "Please enter a value between 0 and 60"[/*:m]
[*]Other -> Enter next command into a string variable: "stringvalue"[/*:m]
[*]Variables -> Set a numeric variable: Numeric variable name "value", variable contents "#stringvalue#"[/*:m]
[*]If: Conditions:
[list]
[*]Compare two strings, values or properties: String 1 "%value%", comparison "less than", string 2 "0"
[/*:m][*]OR: Compare two strings, values or properties: String 1 "%value%", comparison "greater than", string 2 "60"
[/*:m][*]Then:
[list]
[*]Print a message: "I said between 0 and 60!"[/*:m][/list:u]
[/*:m][*]Else: Whatever you want ...[/*:m][/list:u][/*:m][/list:u]
The final script might look like this within QDK:
Print "Please enter a value between 0 and 60:"
Put what the player types next into the "stringvalue" string variable
Change the contents of numeric variable "value" to "#stringvalue#"
If "%value%" is less than "0" or "%value%" is greater than "60" Then Print "I said between 0 and 60!"
or here's the ASL if you want to copy and paste via Notepad:
msg <Please enter a value between 0 and 60:>
enter <stringvalue>
set numeric <value; #stringvalue#>
if ( %value% < 0 ) or ( %value% > 60 ) then msg <I said between 0 and 60!>