Unknown excel password encoding

[hetcat]

hi, buddies, i am new to this hashcat world. i forget password of my excel 2007 file, tried to crack it with office2hashcat.py & office2john.py but all in vain. i don't remember the exact length or any mask characters of the password. i tried all the passwords which i usually used to. it may contain upper case, lower case, numeric, and special characters, with a length of 4 to 12. is there any way to get the exact length of my password or to get only first 3 character of password, without running into weeks or months ??