Error while uploading Journal with wbs element

Hi SAP Folks,

I am trying to upload journal through a customized transaction.

The journal line item has wbs elements in it.

While uploading journal it is showing the below error only when I am using a particular cost element from XXXX Cost element group.

For other cost element from ZZZZ cost element group, it is not showing any error.

ERROR: This G/L Code is only valid for Capital Projects (C-WBS elem.

Is there  any transaction code which will link the cost elements to the project codes.

Please help.

Thanks in advance.