Changing the description of sap standard field

Sir,

In T-code ME61 (Maintain Vendor Evaluation), for documentation field additional text has to be added.

For this purpose i have selected its data element (TXT20) which is in the structure is RM06L,

after that in CMOD T-Code, text enhancements, Keywords, Change. System is giving the option to change the description here.

If i change the description for data element TXT20 where ever this data element is been used will be changed.

My requirement is only to change the particular field in Me61 T-code.

Can any one suggest some other method to do this requirement.

Thanks & Regards.