Custom Field in operation OUTWP

Hello All,

In Time Management we have one operation "OUTWP" which can fetch the fields from IT0001,IT0007,IT0008.

But My Question is, Can we use this Operation OUTWP to fetch the values of Custom Fields from IT0001?

We have some Custom fields in IT0001. we want to process the employees in Time Evaluation using this Custom field value.

So please give me some suggestions to fetch the custom field value in operation OUTWP and also whether it is possible or not by adding some code in program "SAPFP51T".

Thanks in Advance.