part re-naming

how do I name a part in the feature tree to something different than the file name without the instance designator truncating the number?  ex.:  I have a part file in the assembly called EL-RNGTMNL_TB14-14.prt. and instead of EL-RNGTMNL_TB14-14 <1> in the feature tree, I want TB14-14<1>.

Sadly, when I try to rename it, either from prop editor or just click and change, I get TB14<14>  as the CSV is apperently " - ". 

anyone have a way around this beside renaming the file?

thanks

SolidworksParts And Features