You can't use ApplyMap as far as I can tell - however you can use the WHERE clause to iterate and compare with the LIKE operator. Here is a sample of how it works with a small test dataset:
T1: LOAD RowNo() AS T1.R#,* INLINE [
T2: LOAD RowNo() AS T2.R#,* INLINE [
i = NoOfRows('T2');
If( C1 Like Peek('C2',IterNo()-1,'T2') , 1 ) AS Match,
IterNo() AS T2.R#
Be aware that if you have a lot of rows in table T2 then this could be time consuming.
For instance if you have 2000 rows in T1 and 2000 rows in T2 it would perform 4 million LIKE comparisons. However when performing it in a single LOAD with WHILE and IterNo() it is rather quick anyway. Do calculate the number of iterations before you attempt a larger number of rows in any or both of the tables to see if it is feasible and test on a smaller subset first to estimate the time it will take to do the full set of rows.