Sheet number change with Dynamo, getting a Element Set by Parameter error

Hi, I am having some trouble getting this dynamo to work. The idea is to filter the sheets by prefix (we have A2 & A3 depending on project phase) in this instance we are filtering in the A2. Then we are taking the next 3 digits that represent our unit numbers (A00) and changing only those in A2 to A01 in this example. Any help is appreciated.

I think you r feeding the string instead of element to the final part
please copy another filter and filter the element:

I would use a FilterBooleanMask and you don’t need the sorting I don’t think either.

never mind I saw my error, Thanks guys!