Neat way to do it is use the Val() function.

This will return all the numbers on the left of a string until it hits a non-digit value.

e.g. Val("12345-Parkway") returns 12345.

Only gotchas are it returns 0 if there is no numeric part and something like "1 2 3-Parkway" would return 123.

Remember to convert to a string if you are concatenating the value.

i.e. Cstr(Val(Fields!systemname.value))