Help Simply The Update Statement

Hello all,

I need some help in simplyfying the following update statement -

update table <table_a> set <col_1> = NULL where <col_1> = 'N/A'
update table <table_a> set <col_2> = NULL where <col_2> = 'N/A'
update table <table_a> set <col_3> = NULL where <col_3> = 'N/A'
update table <table_a> set <col_4> = NULL where <col_4> = 'N/A'
update table <table_a> set <col_5> = NULL where <col_5> = 'N/A'
update table <table_a> set <col_6> = NULL where <col_6> = 'N/A'
update table <table_a> set <col_7> = NULL where <col_7> = 'N/A'
....and there are 73 columns

Anyway I can create a loop or array and store the column name as a parameter and then pass it to the update statement?

Thanks in advance,
Saurav