Apply String Functions in Workflow

Hello Experts,

We are using Siebel version 20.12,

We have a requirement to test if a workflow process property is included in another process property value (like a string containing a string). To be more clear, I will have a process property called Allowed Channels which will contain comma-delimited values (the process property will come from a system preference), and I will have another process property called Channel and I need to check if the value of Channel is exists in the Allowed Channels

Like : 

Channel = WSC

Allowed Channels = Mobile App, WSC, USSD

In this case, the value will be True, because WSC is one of the allowed channels.