I have following situation:

```
% set a 20
20
% set in_word "Value of a is \$a"
Value of a is $a

```

Now, I would like to print (or set this string to another variable), `Value of a is 20` by operating on the variable `in_word`.

The similar (possibly the simpler case) of dereferecning is covered in an [essay](http://phaseit.net/claird/comp.lang.tcl/tcl_deref.html) which is also linked in Tclers wik [here](http://wiki.tcl.tk/8662). The case covered there is of this nature:

```
% set x y
y
% set y 20
20
% set [set x]
20
%

```

This case parallels with my question in that I have a string with a variable inside it, instead of a direct variable. I am not sure how I can apply the idea in this case to my problem. I tried using `eval` but I did not get the effect I wanted.