Not possible to manipulate text like that using a number format,
if there were only numbers one could use something like

00"K"-00-"E"0

I suspect though that you get this text strings so one way assuming that the
numbers of characters always are 7 you can use a help formula


=LEFT(A1,3)&"-"&MID(A1,4,2)&"-"&RIGHT(A1,2)


then copy and paste special as values in place


Regards,

Peo Sjoblom

"whitmore0112" wrote:

I have a number/text that I want to apply a custom format to, but am not sure
if it is possible. The number/text starts as 12K52E1, and I would like to
apply a number format to always change it to 12K-52-E1. Is it possible?