Actually I have a userform for the Data Entry, there is
one field for Part No. my parts no starts like this

PLU 89
ELE 55
KIT 45
ENG 99

It means the first three cheractors should be text and
last two cheractors are Numaric.

I understood that part... what I want to know is **when** do you want to
restrict the entry. Are you trying to stop the user from typing a bad entry
in while he/she is actually typing? Or do you have an OK button and when
pressed, you want to parse the user's entry to see if it conforms to your
pattern and, if not, send the focus back into the TextBox for the user to
correct the entry? Or did you have some other method in mind?

Rick