Suggests in Formula Editor "Block Selection"

Hi all, I write this because some time ago while i was working on my formulae i don't know how, probabily with a strange combination of keybord, i don't know, but i was able to use the funzion BLOCK SELECTION, i don't know if you know what i mean, closing UF i lost that and i didn't able to replicate because UF doesn't have block selection. So i ask if it's possible to insert this function in UF editor, with block selection i can select a portion of code of also a line and change that portion of code without destroy the lines. For example take this portion of code cr1=real(cz1) cr2=real(cz2) cr3=real(cz3) ci1=imag(cz1) ci2=imag(cz2) ci3=imag(cz3) With the block selection i can select with the mouse, for example, the only REAL part and after i can write IMAGE in all the 3 lines of cr1 2 and 3, i hope you understand what i mean. Sincerely, it's true, i don't know how but i had this funcition for a while in UF. Is it possible?