How to Replace numeric values to character

[vThanu]

data have;
input a;
cards;
12.22
132.113
1.2455
;

run;

Can any one help me how to replace the entire numeric values expect '.' (decimals) with some charater 

expeted result is like below.

xx.xx

xxx.xxx

x.xxxx

[Ksharp]

proc fcmp outlib=work.func.fmt;
function fmt(x) $;
  length y $ 32;
  y=translate(strip(put(x,best32.)),'xxxxxxxxxx','0123456789');
  return (y);
endsub;
run;
options cmplib=work.func;
proc format ;
value xfmt
 low-high=[fmt()];
run;
data have;
input a;
format a xfmt32.;
cards;
12.22
132.113
1.2455
;

run;

[vThanu]

Thank you soo mcuh for you support..