hmmm…
like
*label somename
*set result 0
*comment the label "highest" in the "number"
*comment scene will compare two variables and
*comment store the value (or name if you know how to
*comment work with pointers) in the variable "result"
*gosub_scene number highest (var_1) (var_2)
*gosub_scene number highest (result) (var_3)
*gosub_scene number highest (result) (var_4)
*gosub_scene number highest (result) (var_5)
*gosub_scene number highest (result) (var_6)
*gosub_scene number highest (result) (var_7)
*gosub_scene number highest (result) (var_8)
*gosub_scene number highest (result) (var_9)
*gosub_scene number highest (result) (var_10)
*gosub_scene number highest (result) (var_11)
The higest value is: ${result}
but
I highly sugest do it in a loop so it would be something like this:
*label somename
*set result var_1
*temp parameter ""
*temp i 1
*temp total 11
*label loop
*comment let the looping begin! (11 variables total)
*comment parameter should work as a pointer to val_x
*if (i < total)
*set parameter ("var_"&"${i}")
*gosub_scene number highest (result) ({parameter})
*set i +1
*goto loop
The higest value is: ${result}
Ta DAAAAAA!! 
By the sheer power of coding I command you to return me the Highest value among these variables!
*comment number.txt
*label highest
*param
*if (param_1 > param_2)
*set result param_1
*return
*set result param_2
*return
Done!