use template in gVimPortable
Create you skeleton files to the directory XX\gVimPortable\Data\settings\templates\skeleton.txt.
Add bellow lines to your vimrc file.
augroup templates
au!
" read in templates files
autocmd BufNewFile *.* silent! execute '0r ~\templates\skeleton.'.expand("<afile>:e")
augroup END
When you create a new file using :e xx.txt
in command mode, it will auto load the skeleton file via the file extension.