replace all variables in string in ksh -

I have a string that contains some other variables. I need to convert all of these variables into actual values is.

Example:

  WORD = "AAA" TEXT = "bbb" MY_STRING = `cat temp.file` # after  

I want to get the evaluation string

code> MY_STRING = "Hello AAA, how are you BBB"

this Temp.file can contain different variables (not only WORD and TEXT)

variables that I need to define with $ {NAME} and $ NAME

When Word and Text are part of a different file, Use a dot to include AOL Content:

  Temp.file