I figured out a way to get it done but it is cumbersome.
For anyone who need to know it goes as follows:
Create a calculated field that use NumToText to convert the input number field to a (textfield)
Use Case of If function and the Right function to check
the right most character in the textfield to see if it
contain "0"; if so return 0, if not return 1.
Use the test for numbers 1, 2, 3, 4, 5, 6, 7, 8, 9.
If any of the test return the number 1 then the field
contain other than numeric characters. If not, then the
numeric field can be used for summaries, etc.
James