Remove Letters and Symbols from String

[MrTBC]

I have a field containing strings which consist of a mixture of numbers, letters, symbols, and spaces. There is no pattern to this. I need to remove all characters except the numbers from each one.
e.g. 0171 R321119 (A)
(M)/ 0116 6777745BB
These need to be turned into:
0171321119
01166777745

Any ideas gratefully received.

 

[vidru]

Try this formula:

stringvar test:= "a1b23,)*4(m)5";
stringVar x := "";
numbervar i;
for i := 1 to len(test) do
if isnumeric(Mid (test, i, 1)) then
x := x + Mid (test, i, 1);

x;

-dave

 

[MrTBC]

Thank you very much - that's great.