Substitutes new text for old text in a text string.
SUBSTITUTE(originaltext, oldtext, newtext, which)
In originaltext, removes oldtext, inserts newtext in its place, and returns the result. oldtext and newtext can have different lengths.
which (optional) is a number which specifies which occurrence of oldtext to replace (counting from the left). If omitted, all occurrences are replaced.
SUBSTITUTE("castle", "stl", "v")
SUBSTITUTE("a red red rose", "red", "white")
returns a white white rose. All occurrences of red are replaced if which is omitted.
SUBSTITUTE("a red red rose", "red", "and white", 2)
returns a red and white rose. The second occurrence of red is replaced.