This post is in response to a question on the forums:
"Hi,Using Zoho CRM, I need to provide my users with some custom commands on the Contacts view list. These commands would invoke a custom deluge script."
I've faced this issue in the past. My solution is as follows:
1. Create a checkbox field for the Contacts module called "Run custom function"
2. Create a workflow that checks for field updates to the "Run custom function" field
3. Trigger a custom function from that workflow that does whatever you want and also resets the checkbox to false so that the user can trigger it again. For an example of a custom function, check out my post on quickly generating call logs.
In this way, a user can mass update the checkbox to run custom functions on all of the records.