Syntax for <criteria> field in zoho.crm.searchRecords() function when the value to check against is a variable?

Syntax for <criteria> field in zoho.crm.searchRecords() function when the value to check against is a variable?

I want to search for records in the Tasks module whereby the value of a field (called field1) matches the value stored in a variable in the Deluge script (called variable1).

From the sample code in https://www.zoho.com/deluge/help/crm/search-records.html, it only shows <colVal> that are known and fixed. What is the syntax for the <criteria> argument to achieve this? Is it possible to use zoho.crm.searchRecords() function?