Mix of --hex-charset and non hex ?

[Mem5]

Hi,

I would like to crack this kind of password :

Code:

user\trandom

"user" is constant
"\t" : tab : 0x09
"random" : password I want to guess, i.e. in my wordlists
I tried :

hashcat  -a 7 -1 "user" --hex-charset -2 09 hashfile ?1?2?a?a?a?a?a?a words.dic

Results :

Code:

Invalid hex character detected in mask user

How can I mix the ascii charset with hex charset ?
Thank you.