diff --git a/src/utils/common-expression-helpers.ts b/src/utils/common-expression-helpers.ts
index 34c91c8f8..5f5a50f05 100644
--- a/src/utils/common-expression-helpers.ts
+++ b/src/utils/common-expression-helpers.ts
@@ -280,6 +280,17 @@ export class CommonExpressionHelpers {
     return daySinceLastObs === '' ? '0' : daySinceLastObs;
   };
 
+  generateInfantPTrackerId = (fieldId: string, motherPtrackerId: string): string | undefined => {
+    if (!fieldId || !motherPtrackerId) return;
+  
+    return fieldId === 'infantPtrackerid'
+      ? motherPtrackerId + '1'
+      : fieldId.includes('_')
+      ? motherPtrackerId.concat(fieldId.split('_')[1])
+      : undefined;
+  };
+  
+
   /**
    * Used as wrapper around async functions. It basically evaluates the promised value.
    */