vim - how to expand directory with awk files

Question

I have created a scriptdirectory

let $MYSCRIPTS = $VIM."/vimfiles/my_scripts-docs"

($VIM = C:\Program Files\Vim)

this works fine:

exe "e ".expand('$MYSCRIPTS/vim-calc_vb.txt')

This doesn't work and I can't find out why:

exe "!awk -f ".expand('$MYSCRIPTS/my-awk-script.awk')  
exe "!awk -f ".expand('$MYSCRIPTS\my-awk-script.awk')

error:
awk: fatal: can't open source file 'C:/Program'
It works fine when I put the .awk file in the root but not when
I put it in a vim directory or whatever directory under C:\program files

Why does .txt files expand and .awk files not? How can I let vim know where the awk file is under vimfiles?

Answer 1