try to find out the width of each column. They should have a fixed width.

You are interested in column 2,5,7 and 13

Suppose:

width column 1: 9 chars
width column 2: 6 chars
width column 3+4: 15 chars
width column 5: 10 chars
width column 6: 8 chars
width column 7: 6 chars
width column 8-12: 45 chars
width column 13: 20 chars

ps -u<user> | sed -e "s/.\{9\}\(.\{6\}\).\{15\}\(.\{10\}\).\{8\}\(.\{6\}\).\{45\}\(.\{20\}\)/\4 \1 \2 \3/"