One road to successful playwriting might be to take theater courses at Catholic University and, after graduation, change your name.

James Radomski became James Rado and in 1967 wrote "Hair." That was the same year another ex-student named Mart Crowley wrote "The Boys in the Band," the hit drama about homosexuals which CU's Father Gilbert V. Hartke kept misdescribing as "that hilarious musical comedy."

Jack Miller wrote his play while acting in a regional theaters and at the Hartke with Helen Hayes in "Long Days Journey into Night." He changed his first name to Jason and in 1972 his "That Championship Season" won both the Pulitzer and Drama Critics Circle awards.

Now we have the student actor once programmed as Michael Procaccino. After CU he appeared at Olney under James D. Waring in "The Physicist," at Arena Stage and also at Wayside with such then unknown classmates as Chris and Susan Sarandon. Now he's appearing in Lincoln Center's "The Cherry Orchard" and is the author of a new play introduced at the Los Angeles Mark Taper Forum and at New Haven's Long Wharf. His name is now Michael Cristofer. His play, "The Shadow Box," opens tonight at New York's Morosco and is one of the few distinguished plays of the year.

Checking the Hartke's 1970 opening night program of Cyril Ritchard in "The Devil's Disciple," there's the name of R. Ernest Thompson in the leading role of Dick Dudgeon. As Ernest Thompson, he's this month's cover boy on After Dark magazine and stars in the new ABC Thursday night series, "Westside Medical."

The New Playwrights' Theater 54-hour Dramathon last weekend pulled in a proud $18,011 to the small Church Street playhouse.Friday and Saturday nights the group visits All Soul's Church, 16th and Harvard Streets NW, in a reading of Robert Riche's "Why is That Dumb Son of a Bitch Down the Street Happier Than I Am?" and on Saturday afternoon at 1 All Soul's presents a children's play, "Draco or The Dragon," further details at 232-122. In New York its production of "Hagar's Children continues at the Public Theater, Astor Place.

Pual Michael Glaser of "Starsky and Hutch" will join Cloris Leachman of "Phyllis" for the Irene Ryan Evening of Scenes, a highlight of the American College Theater Festival at the Eisenhower April 10. Winners of 13 regional contests will be completing for top $2,500 prizes to be chosen by a jury of producers, agents and critics.

Shakespeare & Co. will have a four play season from June 8 through Aug. 20 in St. Albans School's Trapier Theater on the Washington Cathedral close. First play will be "Voices of Pride," adapted by Robert Manson Myers from his "The Children of Pride," to be followed by "Scapino" and "As You Like It." On six Saturday afternoons there will be an hour of magic by Dean Adams. Discount tickets will be on sale through April; details at 686-1733.

Slawomir Mrozek's "The Police" is in previews at the Robeson Center, the intimate theater at 1632 O St. NW now officially known as the Paul Robeson International Center for the Performing Arts and Humanistic Study. Performances are Thursdays through Sundays, with the official opening on April 14 under the direction of Norman Gevanthor.

Tonight Arena Stage holds its benefit preview of "The Lower Depths," aiding the Romanian countrymen of its director, Liviu Ciulei . . . Georgetown Classical Theater, a new Shakespearean ensemble, is playing "The Merchant of Venice" through April 12 at Stage Three at 37th and P Streets NW. Details at 625-3104 . . . Arthur Miller's new play, "The Archbishop's Ceiling," will be at the Eisenhower for six weeks starting April 27. On June 14 the Musical Theater Lab atop the Kennedy Center will present "Up from Paradise," a musical re-working of Miller's "The Creation of the World and All That Business" . . . Betty Hughes, drama coordinator for the International Women's Writing Guild, is seeking playscripts by women for the July National Women's Writing Conference at Goucher College; details at 229-3671 . . . Elizabeth French and Michael McElroy, two of the Hayloft Dinner Theater's most popular stars, will appear in the musical "I Do! I Do!" starting Tuesday.