I have never tried this before I'm sure someone else has posted this at least once before. In which episodes did Columbo find himself on a movie set or television studio ?

Requim for a Falling Star is one.
Murder, Smoke and Shadows is another.
Fade Into Murder is yet another.
Caution - Murder Can Be hazardous to your health (although he did not appear on the set).
Double Shock
Suitable for Framing

i'm sure there are others too.

presciption: murder..movie studio
make me a perfect murder..an on-location set
in etude and swan song he appeared in a recording studio.

Close but no cigar examples (heh heh cigar...get it?):

In "Candidate for Crime," he is not in a studio, but he is present when Hayward is taping a political commercial or talk.

In "Murder by the Book," ditto for not being in a studio, but he is present when a TV interview is taped in Franklin's house.

On tape for the news in "Blueprint for Murder"