Hey @Adrian_J
Okay, lets try another way 
Option 1:
Watch this tutorial from Anders Jensen
Option 2: Follow my step by step instructions below
Step 1:
Get your variables into their string variables.
Step 2:
Insert a Matches / FInd Matching Patterns activity.
Step 3: Insert your variables from step 1 into the Properties of the Matches activity (top right). See image below.
Step 4: (See image below)
Click into the ‘Result’ field into the properties panel of the matches activity (see the red circle in the top right). Press ‘Ctrl + K’ can call it ‘Matches_Results’.
Step 5:
Insert a ‘For Each’ activity (Green circle).
Step 6:
Insert the variables ‘Matches_Results’ into the For each.
Step 7:
Insert a log message (Purple circle) with the text exactly
"Result: "+currentItem.ToString
Step 8:
Click run and it should work 
Hopefully combined you have something to help you out
Cheers
Steve