Remove string value from text string in formula

[DesiLogi]

Hello,

Does anyone know, in a formula field in a table, how to remove the value of a text field from another text field? There are 3 fields involved: 

Field1: text255 that contains comma delimited values. 

Field2: text255 that contains a value that may or may not be included in Field1 string value

Field3: formula: removes field2 value  from field1 if that value is in field1 (and does nothing if not). 

For example: 

Field 1 (text255) = 524_789B, 524_788B, 524_794B, 524_791B, 524_1047B

Field 2 (text255)  = 524_794B,

Field 3 (formula) = 524_789B, 524_788B, 524_791B, 524_1047B

What would be the formula for Filed 3 to do this? Many thanks!

[DesiLogi]

I figured out a sort of workaround. The 'Replace' clause will remove a string and replace it with something else. In case anyone needs something like this: 

Field3 formula = Replace([@field:field1],[@field:field2],'')

The only issue is this leaves an extra space where field2 used to be but it works ok otherwise.