With in the Field row values it consider as Cell not the Wildcard match. can you try this way?
Section Access;
Load Access, NTNAME, If(WildMatch([Region Code], '01*', '05*'), [Region Code]) as [Region Code] Inline [
Access, NTNAME, Region Code
USER, PRDQLIKSVR\EAST, 010101
USER, PRDQLIKSVR\WEST, 01*
USER, PRDQLIKSVR\NORTH, 05*
USER, PRDQLIKSVR\WEST, 020201
];
Security Application;
Before develop something, think If placed (The Right information | To the right people | At the Right time | In the Right place | With the Right context)