Regular Expression issue

Hi,
I am looking for a regular expression for money, as my sql server has Money as it's datatype. Acceptable formats for money are
1
1.1
23.1
23.45
1223.00
322.31
[Means upto 4 digit before decimal & 2 digit after decimal]
[Also, no alphabetical character is required] 
[0000.00 or 0.0 or 0  is not acceptable]


Please help
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