Certain pattern in select option / range

For a certain field COMM1, I have to check if it contains a certain pattern 40050/####

where # = numeric characters.

For example:

COMM1 = AB40050/1234CD is valid,

COMM2 = 40050/12ABCD is not valid, since C and D are not numeric characters.

Is this possible via a range ?

Thanks for your feedback