How to create a script that does the following....? (multiple hashings)

[jmmanogsabju]

I suppose your task can't be solved by script. You need specific module for using with hashcat:
md5($salt1.strtoupper(md5($pass)).$salt2)
And yes, this module will be twice slower in comparison with simple MD5.

This makes sense.  Do you have any suggestions on how to develop this module?