While President Reagan stood in the East Room of the White House discussing the country at his press conference yesterday afternoon, five men sat in Room S-207 of the Capitol under a portrait of George Washington and discussed Franklin Delano Roosevelt.

"It will be a testimony to a great president of a great country, who has immeasurably served the country," said Rep. Claude Pepper (D-Fla.).

The testimony to Roosevelt -- a joint session of Congress on Jan. 28 at 11 a.m. to commemorate his 100th birthday -- was the subject of the gathering, which included Pepper, Sen. Jennings Randolph (D-W. Va.), Rep. Charles Bennett (D-Fla.), Peter Kovler, chairman of the FDR National Centennial Committee, and Capt. Peter Cressy, U.S. Navy liaison to Congress.

Much of the news conference was devoted to reminiscing about presidents before and after Roosevelt.

"No one has turned the country more in my time than President Roosevelt, in the first instance," Bennett said, "and President Reagan in the second instance.

"When I was only 6 my father brought me to Washington to sit on the knee of Woodrow Wilson -- the man I'd most like to be like," Bennett remembered. "In those days you didn't need an appointment to see the president. My father drove up in our 10-year-old Chevrolet and we just walked right in.

"Roosevelt was a president of the people," Bennett said. "The world wouldn't be as good today if it weren't for that man."

Plans for the joint session were then explained by Randolph. There will be music by singer Leontyne Price, the U.S. Marine Drum and Bugle Corps, the U.S. Naval Academy Midshipmen Glee Club, remarks by Pepper, Randolph and Averell Harriman, and recordings of speech excerpts by Franklin D. Roosevelt, narrated by his son, James Roosevelt.

"We hope now there will be a rebirth, a renaissance, a rethinking of Roosevelt," said Randolph.