perhaps you can get what you need by using the Exact function to compare text values.
I've tried it with the Exact function but it didn't do the trick.
I've had this problem to and solved it with use of the pattern countfunction.
The name you want to filter = name
code("name") = 101001090009700110
With pattern count it doesn't matter if there are any character in front of behind the string you are searching
Patterncount("984910100109000970011008974" ; code("name"))
Result = 1 (it has found the name you want to filter)