12 cpi on matrix printer

I try to force my dot matrix printer to print in 12 cpi.
At the beginning of the re****t code, I have this command:

  Output {&stream} through value(print-comd) {&misc}.
  Put {&stream} control "~E:".

I saw this control command on an other site.  It is working a time on
25!!
I dont understand!

I have try the command CHR(27) + "E"  It give me to print in bold!
I have try the command CHR(27) + ":"  It give me to print a ":"
alone!!

My printer is a Lexmark

could you help me?