Shortcode modification

Hi all,

I am currently trying to edit a shortcode so that you can provide a site id and it will return the requested object from the provided site id when using a multisite wordpress install. However, due to my lack of php knowledge Iam not sure how to change what site the code will use. If anyone could provide any help or point me to a different shortcode that does something similar I could look at, it would be very helpful.

This is the code I have so far

[Code moderated as per the Forum Rules. Please use the pastebin]