[ferret_users] Shell script arg not working as Ferret variable

[Eowyn.Connolly-Brown@xxxxxxxx]

Greetings Ferreteers, 

Hopefully this is a simple one: 
I have a shell script that takes var1=$argv[1] as a user input, then executes Ferret and carries out several ferret commands. I'm doing some correlation plots, and need to say, eg, 
yes? let p=$var1[x=@ave, y=...]

With this syntax (no space between var1 & [x), the unix shell (tsch) executes the command to open ferret, but complains of "Missing -." 
With a space: 
yes? let p=$var1 [x=@ave,..]
the shell is happy, but ferret has errors because it doesn't recognize var1 [x=..] 
as a valid variable. 

Can I trick Ferret somehow? 

Many thanks! 

A humble newbie, 
Eowyn