SQL QUERY ( replacing characters and special characters in a string)

Database

SQL QUERY ( replacing characters and special characters in a string)

I have 3 columns phone1,phone2,phone3 which are char columns.

my requirement is to concatenate these 3 columns and  Remove Characters and Special Characters and replace with blank.

if the values are like below

phone1 is  123445

Phone2 is 34454F6( Having characters)

phone3 is 333$3#(Having special characters)

then my output must be like below

1234453445463333( oNLY INTEGERS)

how can i achieve this?

kindly help... i am new to teradata

S